Connect++ 0.5.0
A fast, readable connection prover for first-order logic.
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StackProver Class Reference

Prover using a pair of stacks to conduct the proof search. More...

#include <StackProver.hpp>

Collaboration diagram for StackProver:
Collaboration graph
[legend]

Public Member Functions

 StackProver ()
 You only need a basic constructor.
 
 StackProver (const StackProver &)=delete
 Don't try to copy this.
 
 StackProver (const StackProver &&)=delete
 
StackProver & operator= (const StackProver &)=delete
 
StackProver & operator= (const StackProver &&)=delete
 
std::tuple< VariableIndex *, FunctionIndex *, PredicateIndex *, TermIndex * > get_indexes ()
 Straightforward get method.
 
string get_status () const
 Straightforward get method.
 
void set_timeout (chrono::steady_clock::time_point time)
 Set a timeout.
 
void set_problem_path (fs::path &p)
 Set the path for the problem being solved. U.
 
void set_num_preds (size_t)
 Set the number of predicates.
 
void read_from_tptp_file (const string &, bool &, size_t &)
 Obviously, reads a problem from a TPTP file.
 
void add_equality_axioms (Predicate *)
 After reading a problem in which = and/or != appears, add the axioms for equality.
 
void deterministic_reorder (uint32_t n)
 Deterministically reorder the matrix n times.
 
void random_reorder ()
 Randomly reorder the matrix.
 
void random_reorder_literals ()
 Randomly reorder the literals in each clause in the matrix.
 
void show_matrix ()
 Show a nicely formatted matrix.
 
Matrix & get_matrix ()
 Get a reference to the matrix.
 
bool problem_is_cnf_only () const
 Find out whether the problem is CNF only.
 
bool problem_has_true_conjecture () const
 Find out whether the problem's conjecture
is $true.
 
bool problem_has_false_conjecture () const
 Find out whether the problem's conjecture
is $false.
 
bool problem_has_missing_conjecture () const
 Find out whether the problem's conjecture
is missing, in the sense that it didn't appear in the input file.
 
bool problem_has_negated_conjecture_removed () const
 Find out whether the problem's
negated conjecture was simplified out.
 
bool problem_has_fof_axioms () const
 Find out from the parser whether the problem had axioms before simplification.
 
bool simplified_problem_has_fof_axioms () const
 Find out from the parser whether the problem had axioms after simplification.
 
string get_tptp_conversion_string () const
 
void show_tptp_proof ()
 Show a Prolog-formatted proof.
 
ProverOutcome prove ()
 Here is where the magic happens.
 
vector< pair< string, vector< size_t > > > get_internal_proof () const
 Get an internal representation of the proof stack.
 
void show_statistics () const
 Display counts of number of extensions tried and so on.
 
void show_matrix () const
 
void show_path () const
 
void show_stack ()
 
void show_right_stack ()
 
void show_term_index ()
 

Private Member Functions

ProverResult go ()
 This runs the proof search from a given Start Move.
 
void populate_stack_item ()
 Fill the vector of possible actions with everything available.
 
void extend_with_action ()
 Take a single inference (action) and update the stacks accordingly.
 
bool depth_limited ()
 Test for the depth limit.
 
bool axiom () const
 Test to see if you're at an axiom.
 
void process_axiom_forward ()
 Start a right branch to continue from an axiom.
 
void backtrack_once ()
 Basic, single step backtrack on the stack.
 
void reduction_backtrack ()
 One of several different kinds of backtracking.
 
void lemmata_backtrack ()
 One of several different kinds of backtracking.
 
void left_extension_backtrack ()
 One of several different kinds of backtracking.
 
void right_extension_backtrack ()
 One of several different kinds of backtracking.
 
void set_up_start_clauses ()
 The start clauses to use depend on the settings, and the settings can change.
 
void reset_for_start ()
 Reset everything so that you can start from a specified start clause.
 

Private Attributes

size_t num_preds
 How many prdicates does the problem of interest have?
 
VariableIndex var_index
 This class needs one of each kind of index to keep track of Variables, Terms etc.
 
FunctionIndex fun_index
 This class needs one of each kind of index to keep track of Variables, Terms etc.
 
TermIndex term_index
 This class needs one of each kind of index to keep track of Variables, Terms etc.
 
PredicateIndex pred_index
 This class needs one of each kind of index to keep track of Variables, Terms etc.
 
SubstitutionStack sub_stack
 There is a separate stack to make application and removal of substitutions straightforward.
 
vector< StartClauseStatus > results
 This is populated by the StackProver::set_up_start_clauses method.
 
Matrix matrix
 A copy of the matrix you're working with.
 
SimplePath path
 At any point in the search process this is a copy of the path for the current node in the proof being constructed.
 
Clause new_C
 At any point in the search process this is a copy of the clause for the current node in the proof being constructed.
 
Lemmata lemmata
 At any point in the search process this is a copy of the list of lemmata for the current node in the proof being constructed.
 
Unifier u
 We need a single Unifier to use throught the process.
 
InferenceItem action
 Stores the next action from the current StackItem.
 
StackItem * si
 Pointer to the current StackItem.
 
uint32_t current_depth_limit
 Self-explanatary.
 
uint32_t current_depth
 Self-explanatary.
 
bool depth_limit_reached
 Self-explanatary.
 
string status
 Problem status, if found in input file.
 
string tptp_conversion_string
 TPTP-friendly description of the clause conversion.
 
vector< StackItem > stack
 Main stack: this is constructed by the search process and, if completed, represents a proof.
 
vector< StackItem > right_branch_stack
 We build the proof by trying the left branches of extensions first: this stack keeps track of the right branches that we need to come back to.
 
bool backtrack
 Are we moving up or down the stack?
 
ProofPrinter proof_printer
 You need one of these to print LaTeX output or any kind of proof certificate.
 
fs::path problem_path
 Path for the problem of interest.
 
Interval output_interval
 How often do you output updates about progress?
 
uint32_t proof_count
 If we're searching for multiple proofs, keep count
of which one this is.
 
bool use_timeout
 Are we using a timeout?
 
chrono::steady_clock::time_point end_time
 When do we stop because of a timeout?
 
verbose_print::VPrint show
 Set up printing according to verbosity.
 
bool cnf_only
 Keep track of whether there were any FOF formulas in the problem file.
 
bool conjecture_true
 Keep track of whether the parser found the conjecture to be true.
 
bool conjecture_false
 Keep track of whether the parser found the conjecture to be false.
 
bool conjecture_missing
 Keep track of whether the parser found a conjecture in the problem file.
 
bool negated_conjecture_removed
 Keep track of whether the parser simplified the conjecture away.
 
bool fof_has_axioms
 Keep track of whether the parser found that it's an FOF problem with axioms before simplification.
 
bool simplified_fof_has_axioms
 Keep track of whether the parser found that it's an FOF problem with axioms after simplification.
 

Static Private Attributes

static uint32_t reductions_tried = 0
 We'll be keeping some simple statistics about the search process.
 
static uint32_t extensions_tried = 0
 We'll be keeping some simple statistics about the search process.
 
static uint32_t lemmata_tried = 0
 We'll be keeping some simple statistics about the search process.
 
static uint32_t right_branches_started = 0
 We'll be keeping some simple statistics about the search process.
 

Friends

ostream & operator<< (ostream &, const StackProver &)
 

Detailed Description

Prover using a pair of stacks to conduct the proof search.

This version is a straightforward translation of the proof method to search for a tree with all its leaves being axioms. However, by not using recursion we retain the ability to fully control backtracking and therefore, amongst other things, find all possible proofs.

This is really the main class for Connect++, and everything else essentially exists to support it. There's a lot going on here so hang on to your hat!

This is also one of only a small number of places where you'll need to modify stuff to incorporate machine learning. The main advice is simple: take notice of the comments that point out where to do this, and be very careful to leave the general stack manipulation code alone unless you really know what you're doing, because that stuff is quite easy to break.

Definition at line 74 of file StackProver.hpp.

Constructor & Destructor Documentation

◆ StackProver()

StackProver::StackProver ( )

You only need a basic constructor.

Definition at line 33 of file StackProver.cpp.

34: num_preds(0)
35, var_index()
36, fun_index()
37, term_index()
38, pred_index()
39, sub_stack()
40, results()
41, matrix()
42, path()
43, new_C()
44, lemmata()
45, u()
46, action(InferenceItemType::Start)
47, si(nullptr)
48, current_depth_limit(0)
49, current_depth(1)
50, depth_limit_reached(false)
51, status()
52, tptp_conversion_string()
53, stack()
54, right_branch_stack()
55, backtrack(false)
56, proof_printer(&stack)
57, problem_path()
58, output_interval(params::output_frequency)
59, proof_count(0)
60, use_timeout(false)
61, end_time()
62, show(params::verbosity)
63, cnf_only(false)
64, conjecture_true(false)
65, conjecture_false(false)
66, conjecture_missing(false)
67, negated_conjecture_removed(false)
68, fof_has_axioms(false)
69, simplified_fof_has_axioms(false)
70{}
StackProver::depth_limit_reached
bool depth_limit_reached
Self-explanatary.
Definition StackProver.hpp:168
StackProver::status
string status
Problem status, if found in input file.
Definition StackProver.hpp:172
StackProver::results
vector< StartClauseStatus > results
This is populated by the StackProver::set_up_start_clauses method.
Definition StackProver.hpp:116
StackProver::negated_conjecture_removed
bool negated_conjecture_removed
Keep track of whether the parser simplified the conjecture away.
Definition StackProver.hpp:343
StackProver::current_depth_limit
uint32_t current_depth_limit
Self-explanatary.
Definition StackProver.hpp:160
StackProver::action
InferenceItem action
Stores the next action from the current StackItem.
Definition StackProver.hpp:146
StackProver::num_preds
size_t num_preds
How many prdicates does the problem of interest have?
Definition StackProver.hpp:80
StackProver::fof_has_axioms
bool fof_has_axioms
Keep track of whether the parser found that it's an FOF problem with axioms before simplification.
Definition StackProver.hpp:348
StackProver::stack
vector< StackItem > stack
Main stack: this is constructed by the search process and, if completed, represents a proof.
Definition StackProver.hpp:181
StackProver::matrix
Matrix matrix
A copy of the matrix you're working with.
Definition StackProver.hpp:120
StackProver::pred_index
PredicateIndex pred_index
This class needs one of each kind of index to keep track of Variables, Terms etc.
Definition StackProver.hpp:100
StackProver::right_branch_stack
vector< StackItem > right_branch_stack
We build the proof by trying the left branches of extensions first: this stack keeps track of the rig...
Definition StackProver.hpp:187
StackProver::proof_printer
ProofPrinter proof_printer
You need one of these to print LaTeX output or any kind of proof certificate.
Definition StackProver.hpp:196
StackProver::cnf_only
bool cnf_only
Keep track of whether there were any FOF formulas in the problem file.
Definition StackProver.hpp:327
StackProver::path
SimplePath path
At any point in the search process this is a copy of the path for the current node in the proof being...
Definition StackProver.hpp:126
StackProver::fun_index
FunctionIndex fun_index
This class needs one of each kind of index to keep track of Variables, Terms etc.
Definition StackProver.hpp:90
StackProver::lemmata
Lemmata lemmata
At any point in the search process this is a copy of the list of lemmata for the current node in the ...
Definition StackProver.hpp:138
StackProver::current_depth
uint32_t current_depth
Self-explanatary.
Definition StackProver.hpp:164
StackProver::tptp_conversion_string
string tptp_conversion_string
TPTP-friendly description of the clause conversion.
Definition StackProver.hpp:176
StackProver::simplified_fof_has_axioms
bool simplified_fof_has_axioms
Keep track of whether the parser found that it's an FOF problem with axioms after simplification.
Definition StackProver.hpp:353
StackProver::conjecture_missing
bool conjecture_missing
Keep track of whether the parser found a conjecture in the problem file.
Definition StackProver.hpp:339
StackProver::term_index
TermIndex term_index
This class needs one of each kind of index to keep track of Variables, Terms etc.
Definition StackProver.hpp:95
StackProver::proof_count
uint32_t proof_count
If we're searching for multiple proofs, keep count of which one this is.
Definition StackProver.hpp:232
StackProver::conjecture_false
bool conjecture_false
Keep track of whether the parser found the conjecture to be false.
Definition StackProver.hpp:335
StackProver::var_index
VariableIndex var_index
This class needs one of each kind of index to keep track of Variables, Terms etc.
Definition StackProver.hpp:85
StackProver::conjecture_true
bool conjecture_true
Keep track of whether the parser found the conjecture to be true.
Definition StackProver.hpp:331
StackProver::backtrack
bool backtrack
Are we moving up or down the stack?
Definition StackProver.hpp:191
StackProver::end_time
chrono::steady_clock::time_point end_time
When do we stop because of a timeout?
Definition StackProver.hpp:240
StackProver::si
StackItem * si
Pointer to the current StackItem.
Definition StackProver.hpp:156
StackProver::new_C
Clause new_C
At any point in the search process this is a copy of the clause for the current node in the proof bei...
Definition StackProver.hpp:132
StackProver::problem_path
fs::path problem_path
Path for the problem of interest.
Definition StackProver.hpp:200
StackProver::use_timeout
bool use_timeout
Are we using a timeout?
Definition StackProver.hpp:236
StackProver::sub_stack
SubstitutionStack sub_stack
There is a separate stack to make application and removal of substitutions straightforward.
Definition StackProver.hpp:105
StackProver::show
verbose_print::VPrint show
Set up printing according to verbosity.
Definition StackProver.hpp:244
StackProver::u
Unifier u
We need a single Unifier to use throught the process.
Definition StackProver.hpp:142
StackProver::output_interval
Interval output_interval
How often do you output updates about progress?
Definition StackProver.hpp:204

Member Function Documentation

◆ add_equality_axioms()

void StackProver::add_equality_axioms ( Predicate * equals_predicate)

After reading a problem in which = and/or != appears, add the axioms for equality.

Parameters
equals_predicatePointer to a Predicate representing equals. This will have been obtained as an output from parsing the input file.

Definition at line 127 of file StackProver.cpp.

127 {
128 /*
129 * Equality axioms as described in Handbook of Automated
130 * Reasoning, Volume 1, page 615.
131 */
132 Arity max_fun_arity = fun_index.find_maximum_arity();
133 Arity max_pred_arity = pred_index.find_maximum_arity();
134 /*
135 * You need at least three variables to describe these, and
136 * twice as many as the arity of the biggest predicate or
137 * function.
138 */
139 uint32_t max_arity = max_fun_arity;
140 if (max_pred_arity > max_arity)
141 max_arity = max_pred_arity;
142 if (max_arity < 3)
143 max_arity = 3;
144 vector<Term*> xs;
145 vector<Term*> ys;
146 string xvar("__eqx_");
147 string yvar("__eqy_");
148 for (size_t i = 0; i < max_arity; i++) {
149 Variable* xvarp = var_index.add_named_var(xvar + std::to_string(i));
150 Variable* yvarp = var_index.add_named_var(yvar + std::to_string(i));
151 xs.push_back(term_index.add_variable_term(xvarp));
152 ys.push_back(term_index.add_variable_term(yvarp));
153 }
154 /*
155 * How you construct these depends on which representation you're using.
156 * It's easy enough to show that the difference is only a case
157 * of swapping negations. See for example "Equality Preprocessing in
158 * Connection Calculi", Oliver and Otten.
159 */
160 bool pol = !params::positive_representation;
161 uint32_t n_added = 0;
162 /*
163 * Axiom for reflexivity.
164 */
165 vector<Term*> ref;
166 ref.push_back(xs[0]);
167 ref.push_back(xs[0]);
168 Literal reflexive(equals_predicate, ref, 2, pol);
169 Clause ref_c;
170 ref_c.add_lit(reflexive);
171 matrix.add_clause(ref_c, "equality");
172 n_added++;
173 /*
174 * Axiom for symmetry.
175 */
176 vector<Term*> xy;
177 xy.push_back(xs[0]);
178 xy.push_back(xs[1]);
179 vector<Term*> yx;
180 yx.push_back(xs[1]);
181 yx.push_back(xs[0]);
182 Literal sym1(equals_predicate, xy, 2, !pol);
183 Literal sym2(equals_predicate, yx, 2, pol);
184 Clause sym_c;
185 sym_c.add_lit(sym1);
186 sym_c.add_lit(sym2);
187 matrix.add_clause(sym_c, "equality");
188 n_added++;
189 /*
190 * Axiom for transitivity.
191 */
192 vector<Term*> yz;
193 yz.push_back(xs[1]);
194 yz.push_back(xs[2]);
195 vector<Term*> xz;
196 xz.push_back(xs[0]);
197 xz.push_back(xs[2]);
198 Literal tr1(equals_predicate, xy, 2, !pol);
199 Literal tr2(equals_predicate, yz, 2, !pol);
200 Literal tr3(equals_predicate, xz, 2, pol);
201 Clause tr_c;
202 tr_c.add_lit(tr1);
203 tr_c.add_lit(tr2);
204 tr_c.add_lit(tr3);
205 matrix.add_clause(tr_c, "equality");
206 n_added++;
207 /*
208 * Function substitution.
209 */
210 for (size_t j = 0; j < fun_index.get_size(); j++) {
211 Function* p = fun_index[j];
212 Arity ar = p->get_arity();
213 if (ar > 0) {
214 Clause c;
215 vector<Term*> x1xn;
216 vector<Term*> y1yn;
217 for (size_t i = 0; i < ar; i++) {
218 x1xn.push_back(xs[i]);
219 y1yn.push_back(ys[i]);
220 vector<Term*> xiyi;
221 xiyi.push_back(xs[i]);
222 xiyi.push_back(ys[i]);
223 Literal eq_lit(equals_predicate, xiyi, 2, !pol);
224 c.add_lit(eq_lit);
225 }
226 vector<Term*> t;
227 t.push_back(term_index.add_function_term(p, x1xn));
228 t.push_back(term_index.add_function_term(p, y1yn));
229 Literal f_lit(equals_predicate, t, 2, pol);
230 c.add_lit(f_lit);
231 matrix.add_clause(c, "equality");
232 n_added++;
233 }
234 }
235 /*
236 * Predicate substitution.
237 */
238 for (size_t j = 0; j < pred_index.get_num_preds(); j++) {
239 Predicate* p = pred_index[j];
240 Arity ar = p->get_arity();
241 if (ar > 0 && p != equals_predicate) {
242 Clause c;
243 vector<Term*> x1xn;
244 vector<Term*> y1yn;
245 for (size_t i = 0; i < ar; i++) {
246 x1xn.push_back(xs[i]);
247 y1yn.push_back(ys[i]);
248 vector<Term*> xiyi;
249 xiyi.push_back(xs[i]);
250 xiyi.push_back(ys[i]);
251 Literal eq_lit(equals_predicate, xiyi, 2, !pol);
252 c.add_lit(eq_lit);
253 }
254 Literal p_lit1(p, x1xn, ar, !pol);
255 Literal p_lit2(p, y1yn, ar, pol);
256 c.add_lit(p_lit1);
257 c.add_lit(p_lit2);
258 matrix.add_clause(c, "equality");
259 n_added++;
260 }
261 }
262 /*
263 * Distinct objects
264 */
265 Arity min_arity = fun_index.find_minimum_arity();
266 if (!params::no_distinct_objects && min_arity == 0) {
267 vector<Term*> all_distinct_constants;
268 vector<Term*> empty_args;
269 for (size_t i = 0; i < fun_index.get_size(); i++) {
270 Function* p = fun_index[i];
271 Arity ar = p->get_arity();
272 // Remember, you don't want to do this for Skolem constants.
273 string name = p->get_name();
274 string prefix = name.string::substr(0,params::unique_skolem_prefix.length());
275 bool is_skolem = (params::unique_skolem_prefix.string::compare(0, string::npos, prefix) == 0) &&
276 (params::unique_skolem_prefix.length() < name.length());
277 bool is_quoted = (name[0] == '\"' && name[name.size() - 1] == '\"');
278 if (ar == 0 &&
279 !is_skolem &&
280 (params::all_distinct_objects || is_quoted)) {
281 Term* t = term_index.add_function_term(p, empty_args);
282 all_distinct_constants.push_back(t);
283 }
284 }
285 size_t s = all_distinct_constants.size();
286 if (s > 1) {
287 for (size_t i = s - 1; i > 0; i--) {
288 for (size_t j = 0; j < i; j++) {
289 Clause c;
290 vector<Term*> args;
291 args.push_back(all_distinct_constants[i]);
292 args.push_back(all_distinct_constants[j]);
293 Literal eq_lit(equals_predicate, args, 2, !pol);
294 c.add_lit(eq_lit);
295 matrix.add_clause(c, "distinct_objects");
296 n_added++;
297 }
298 }
299 }
300 }
301 matrix.set_num_equals(n_added);
302}
Clause
Representation of clauses.
Definition Clause.hpp:52
Clause::add_lit
void add_lit(const Literal &)
Add a literal, making sure you don't duplicate.
Definition Clause.cpp:87
Function
Basic representation of functions.
Definition Function.hpp:54
Function::get_arity
Arity get_arity() const
Most basic access function.
Definition Function.hpp:89
Function::get_name
string get_name() const
Most basic access function.
Definition Function.hpp:85
FunctionIndex::find_minimum_arity
Arity find_minimum_arity() const
Find the smallest arity appearing for any Function in the index.
Definition FunctionIndex.cpp:81
FunctionIndex::get_size
size_t get_size() const
Self-explanatory.
Definition FunctionIndex.hpp:96
FunctionIndex::find_maximum_arity
Arity find_maximum_arity() const
Find the largest arity appearing for any Function in the index.
Definition FunctionIndex.cpp:71
Literal
Basic representation of literals, bundling together (pointers to) a Predicate, a collection of argume...
Definition Literal.hpp:50
Matrix::add_clause
void add_clause(Clause &, string="")
Add a Clause to the Matrix and update the index accordingly.
Definition Matrix.cpp:91
Matrix::set_num_equals
void set_num_equals(uint32_t n)
Straightforward set method.
Definition Matrix.hpp:259
Predicate
Basic representation of predicates: here just names, ids and arities.
Definition Predicate.hpp:51
Predicate::get_arity
Arity get_arity() const
Basic get method.
Definition Predicate.hpp:90
PredicateIndex::get_num_preds
size_t get_num_preds() const
Basic get method.
Definition PredicateIndex.hpp:92
PredicateIndex::find_maximum_arity
Arity find_maximum_arity() const
Find the largest arity appearing in the index.
Definition PredicateIndex.cpp:66
Term
General representation of terms.
Definition Term.hpp:62
TermIndex::add_function_term
Term * add_function_term(Function *, const vector< Term * > &)
Self-explanatory: add a Term containing a function to the index.
Definition TermIndex.cpp:73
TermIndex::add_variable_term
Term * add_variable_term(Variable *)
Self-explanatory: add a Term containing a variable to the index.
Definition TermIndex.cpp:56
Variable
Basic representation of variables.
Definition Variable.hpp:58
VariableIndex::add_named_var
Variable * add_named_var(const string &)
Add a variable with the specified name to the index.
Definition VariableIndex.cpp:44

◆ axiom()

bool StackProver::axiom ( ) const
private

Test to see if you're at an axiom.

Definition at line 354 of file StackProver.cpp.

354 {
355 return si->c.empty();
356}
Clause::empty
bool empty() const
Straightforward get method.
Definition Clause.hpp:82
StackItem::c
Clause c
Each node in the proof tree is a tuple of clause, matrix, path, lemmata: this is the clause.
Definition StackItem.hpp:60

◆ backtrack_once()

void StackProver::backtrack_once ( )
private

Basic, single step backtrack on the stack.

Careful though: you need to treat the depth of the tree correctly if you want to keep track of it.

Definition at line 560 of file StackProver.cpp.

560 {
561 backtrack = true;
562 stack.pop_back();
563 si = &stack.back();
564 current_depth = si->depth;
565}
StackItem::depth
uint32_t depth
How deep in the proof tree are we?
Definition StackItem.hpp:88

◆ depth_limited()

bool StackProver::depth_limited ( )
private

Test for the depth limit.

Definition at line 345 of file StackProver.cpp.

345 {
346 bool result = ((params::limit_by_tree_depth && (current_depth >= current_depth_limit))
347 ||
348 (!params::limit_by_tree_depth && (si->p.length() >= current_depth_limit)));
349 if (result)
350 depth_limit_reached = true;
351 return result;
352}
SimplePath::length
uint32_t length() const
Straightforward get method.
Definition SimplePath.hpp:93
StackItem::p
SimplePath p
Each node in the proof tree is a tuple of clause, matrix, path, lemmata: this is the path.
Definition StackItem.hpp:65

◆ deterministic_reorder()

void StackProver::deterministic_reorder ( uint32_t n)
inline

Deterministically reorder the matrix n times.

Parameters
nNumber of times to reorder.

Definition at line 430 of file StackProver.hpp.

430 {
431 matrix.deterministic_reorder(n);
432 }
Matrix::deterministic_reorder
void deterministic_reorder(size_t)
Deterministic reorder of the clauses.
Definition Matrix.cpp:105

◆ extend_with_action()

void StackProver::extend_with_action ( )
private

Take a single inference (action) and update the stacks accordingly.

Definition at line 358 of file StackProver.cpp.

358 {
359 /*
360 * Add a new StackItem using the next action from the list stored
361 * in the StackItem currently in play. If necessary, also
362 * add something to right_branch_stack. Populate the new list of
363 * actions and update si.
364 */
365 action = si->actions.back();
366 si->actions.pop_back();
367 current_depth++;
368 /*
369 * Why are the scope rules for switch so odd???
370 */
371 Clause old_C;
372 Lemmata old_Lem;
373 Literal neg_lit;
374 UnificationOutcome outcome;
375 Substitution sig;
376 switch (action.T) {
377 //----------------------------------------------------------------------
378 //----------------------------------------------------------------------
379 //----------------------------------------------------------------------
380 // Lemmata.
381 //----------------------------------------------------------------------
382 //----------------------------------------------------------------------
383 //----------------------------------------------------------------------
384 case InferenceItemType::Lemma:
385 lemmata_tried++;
386 /*
387 * If you are restricting backtracking for lemmata then
388 * at this point you can remove all alternatives.
389 */
390 if (params::limit_bt_lemmas)
391 si->restrict_backtrack();
392 /*
393 * Work out the new state.
394 */
395 new_C = si->c;
396 new_C.drop_literal(action.Lindex);
397 path = si->p;
398 lemmata = si->l;
399 /*
400 * Extend the stack.
401 */
402 stack.push_back(StackItem(StackItemType::Lemmata, new_C, path,
403 lemmata, current_depth));
404 stack.back().set_this_action(action);
405 break;
406 //----------------------------------------------------------------------
407 //----------------------------------------------------------------------
408 //----------------------------------------------------------------------
409 // Reduction.
410 //----------------------------------------------------------------------
411 //----------------------------------------------------------------------
412 //----------------------------------------------------------------------
413 case InferenceItemType::Reduction:
414 reductions_tried++;
415 /*
416 * If you are restricting backtracking for reductions then
417 * at this point you can remove all alternatives.
418 */
419 if (params::limit_bt_reductions)
420 si->restrict_backtrack();
421 /*
422 * Reductions have a substitution, so apply it and remember
423 * in case you need to undo it later.
424 */
425 action.sigma.apply();
426 sub_stack.push_all(action.sigma);
427 /*
428 * Work out the new state.
429 */
430 new_C = si->c;
431 new_C.drop_literal(action.Lindex);
432 path = si->p;
433 lemmata = si->l;
434 lemmata.push_back(action.L);
435 /*
436 * Extend the stack.
437 */
438 stack.push_back(StackItem(StackItemType::Reduction, new_C, path,
439 lemmata, action.sigma, current_depth));
440 stack.back().set_this_action(action);
441 break;
442 //----------------------------------------------------------------------
443 //----------------------------------------------------------------------
444 //----------------------------------------------------------------------
445 // Extension.
446 //----------------------------------------------------------------------
447 //----------------------------------------------------------------------
448 //----------------------------------------------------------------------
449 case InferenceItemType::Extension:
450 extensions_tried++;
451 /*
452 * You're going to generate new variables, so remember where to
453 * backtrack to.
454 */
455 var_index.add_backtrack_point();
456 /*
457 * This is an Extension, so you're going to add something to
458 * right_branch_stack.
459 */
460 path = si->p;
461 old_C = si->c;
462 old_C.drop_literal(action.Lindex);
463 old_Lem = si->l;
464 old_Lem.push_back(action.L);
465 /*
466 * DON'T do populate_stack_item here! That can wait until you actually
467 * use the right branch. In fact it *has* to wait because we might
468 * apply substitutions that affect it.
469 */
470 right_branch_stack.push_back(StackItem(StackItemType::RightBranch, old_C,
471 path, old_Lem, current_depth));
472 /*
473 * The right branch needs to know where to restrict backtracking.
474 */
475 right_branch_stack.back().set_bt_restriction_index(stack.size() - 1);
476 /*
477 * Now you can deal with the left branch.
478 */
479 new_C = matrix[action.C_2].make_copy_with_new_vars(var_index, term_index);
480 /*
481 * Extensions have a substitution, so apply it and remember
482 * in case you need to undo it later.
483 */
484 neg_lit = action.L;
485 neg_lit.invert();
486 outcome = u(neg_lit, new_C[action.Lprime]);
487 sig = u.get_substitution();
488 u.backtrack();
489 sig.apply();
490 sub_stack.push_all(sig);
491 /*
492 * Work out the new state.
493 */
494 new_C.drop_literal(action.Lprime);
495 path.push(action.L);
496 lemmata = si->l;
497 /*
498 * Extend the stack.
499 */
500 stack.push_back(StackItem(StackItemType::LeftBranch, new_C, path,
501 lemmata, sig, current_depth));
502 stack.back().set_this_action(action);
503 break;
504 default:
505 cerr << "PANIC!!! You should only have a lemmata, reduction or an extension here!"
506 << endl;
507 break;
508 }
509 /*
510 * Finally, move si on and work out the next bunch of possible actions.
511 */
512 si = &stack.back();
513 populate_stack_item();
514}
Clause::drop_literal
void drop_literal(LitNum)
Get rid of the specified Literal.
Definition Clause.cpp:135
Lemmata
Representation of the lemma list.
Definition Lemmata.hpp:49
Lemmata::push_back
void push_back(const Literal &)
Self-explanatory.
Definition Lemmata.cpp:28
StackProver::lemmata_tried
static uint32_t lemmata_tried
We'll be keeping some simple statistics about the search process.
Definition StackProver.hpp:222
StackProver::populate_stack_item
void populate_stack_item()
Fill the vector of possible actions with everything available.
Definition StackProver.cpp:304
StackProver::extensions_tried
static uint32_t extensions_tried
We'll be keeping some simple statistics about the search process.
Definition StackProver.hpp:217
StackProver::reductions_tried
static uint32_t reductions_tried
We'll be keeping some simple statistics about the search process.
Definition StackProver.hpp:212
Substitution
General representation of a substitution.
Definition Substitution.hpp:57
Substitution::apply
void apply() const
Apply a substitution everywhere.
Definition Substitution.cpp:56
SubstitutionStack::push_all
void push_all(Substitution &)
Take all the substitutions provided and add the corresponding variables to the stack.
Definition SubstitutionStack.cpp:28
Unifier::backtrack
void backtrack()
Apply the backtracking process to the substitution that has been constructed.
Definition Unifier.cpp:134
Unifier::get_substitution
Substitution get_substitution() const
Trivial get methods for the result.
Definition Unifier.hpp:116
VariableIndex::add_backtrack_point
void add_backtrack_point()
Add a backtrack point.
Definition VariableIndex.cpp:125
InferenceItem::Lindex
LitNum Lindex
The index of the literal within the clause being used.
Definition InferenceItem.hpp:73
InferenceItem::Lprime
LitNum Lprime
The index of the literal in C_2 being used.
Definition InferenceItem.hpp:82
InferenceItem::sigma
Substitution sigma
A copy of the substitution that makes the rule applicable. This may or may not be reusable,...
Definition InferenceItem.hpp:89
InferenceItem::L
Literal L
The Literal that is used to make the inference.
Definition InferenceItem.hpp:69
InferenceItem::C_2
ClauseNum C_2
For extensions, the number of the clause for which a fresh copy is being made.
Definition InferenceItem.hpp:78
InferenceItem::T
InferenceItemType T
What kind of inference is this?
Definition InferenceItem.hpp:65
StackItem
Stack items: each contains its own stack of possible next inferences.
Definition StackItem.hpp:51
StackItem::restrict_backtrack
void restrict_backtrack()
Adjust the collection of actions to limit backtracking.
Definition StackItem.cpp:51
StackItem::actions
vector< InferenceItem > actions
Actions available to try.
Definition StackItem.hpp:84
StackItem::l
Lemmata l
Each node in the proof tree is a tuple of clause, matrix, path, lemmata: this is the lemmata.
Definition StackItem.hpp:70

◆ get_indexes()

std::tuple< VariableIndex *, FunctionIndex *, PredicateIndex *, TermIndex * > StackProver::get_indexes ( )
inline

Straightforward get method.

Definition at line 369 of file StackProver.hpp.

369 {
370 auto result = std::make_tuple(&var_index, &fun_index, &pred_index, &term_index);
371 return result;
372 }

◆ get_internal_proof()

vector< pair< string, vector< size_t > > > StackProver::get_internal_proof ( ) const

Get an internal representation of the proof stack.

Definition at line 1244 of file StackProver.cpp.

1244 {
1245 return proof_printer.make_internal();
1246}
ProofPrinter::make_internal
vector< pair< string, vector< size_t > > > make_internal() const
Make a simple data structure representing the proof stack.
Definition ProofPrinter.cpp:339

◆ get_matrix()

Matrix & StackProver::get_matrix ( )
inline

Get a reference to the matrix.

Definition at line 456 of file StackProver.hpp.

456 {
457 return matrix;
458 };

◆ get_status()

string StackProver::get_status ( ) const
inline

Straightforward get method.

Definition at line 376 of file StackProver.hpp.

376{ return status; }

◆ get_tptp_conversion_string()

string StackProver::get_tptp_conversion_string ( ) const
inline

Definition at line 509 of file StackProver.hpp.

509 {
510 return tptp_conversion_string;
511 }

◆ go()

ProverResult StackProver::go ( )
private

This runs the proof search from a given Start Move.

Definition at line 669 of file StackProver.cpp.

669 {
670 /*
671 * Having set up a single entry on the stack, containing a start
672 * state, search for a proof.
673 *
674 * Either you return by ending at the start state with nothing left
675 * to try, by finding a proof, by depth limiting or by timing out.
676 *
677 * The backtrack variable is important here - when true you are
678 * (surprise surprise) backtracking. So mostly each case in the
679 * following switch is divided according to whether you're going
680 * forward or backtracking.
681 */
682 while(true) {
683 /*
684 * Test for and deal with a timeout.
685 */
686 if (use_timeout && chrono::steady_clock::now() > end_time)
687 return ProverResult::TimeOut;
688 /*
689 * Say what's going on.
690 */
691 if (output_interval.tick() && params::verbosity >= 2) {
692 cout << cursor_symbols::Cursor::to_column(1);
693 cout << cursor_symbols::Cursor::erase_line(2);
694 cout << "Reductions: " << reductions_tried << " Extensions: " << extensions_tried;
695 cout << " Lemmata: " << lemmata_tried << " Right branches: " << right_branches_started;
696 cout << " Stack size: " << stack.size();
697 cout.flush();
698 }
699 /*
700 * si must point to the back of the stack at this point.
701 *
702 * Remember that extend_with_action will deal with this for you.
703 */
704 switch (si->item_type) {
705 //----------------------------------------------------------------
706 //----------------------------------------------------------------
707 //----------------------------------------------------------------
708 // Deal with the start state. Essentially straightforward. Just
709 // deal with a completed search, otherwise work out the
710 // possibly actions and get on with it.
711 //----------------------------------------------------------------
712 //----------------------------------------------------------------
713 //----------------------------------------------------------------
714 case StackItemType::Start:
715 backtrack = false;
716 if (si->actions.empty())
717 return ProverResult::OptionsExhausted;
718 else
719 extend_with_action();
720 break;
721 //----------------------------------------------------------------
722 //----------------------------------------------------------------
723 //----------------------------------------------------------------
724 // Lemmata. Again, mostly straightforward.
725 //----------------------------------------------------------------
726 //----------------------------------------------------------------
727 //----------------------------------------------------------------
728 case StackItemType::Lemmata:
729 /*
730 * Operation is essentially similar to the reduction case.
731 *
732 * First deal with moving forward.
733 */
734 if (!backtrack) {
735 if (axiom()) {
736 /*
737 * Either you've found a proof or you try a right branch.
738 */
739 if (right_branch_stack.empty())
740 return ProverResult::Valid;
741 else
742 process_axiom_forward();
743 }
744 /*
745 * Backtrack because of depth limiting.
746 */
747 else if (depth_limited() && params::depth_limit_all)
748 lemmata_backtrack();
749 /*
750 * Backtrack because there's nothing left to try.
751 */
752 else if (si->actions.empty())
753 lemmata_backtrack();
754 /*
755 * There must be something left to try, so try it.
756 */
757 else
758 extend_with_action();
759 }
760 /*
761 * We are moving down the stack.
762 */
763 else {
764 /*
765 * If you're backtracking then you need to jump over axioms.
766 */
767 if (axiom())
768 lemmata_backtrack();
769 /*
770 * If you're not at an axiom then you can start going forward
771 * again.
772 */
773 else
774 backtrack = false;
775 }
776 break;
777 //----------------------------------------------------------------
778 //----------------------------------------------------------------
779 //----------------------------------------------------------------
780 // Reduction. Almost identical to Lemmata, but note the
781 // slightly different backtracking requirement to take account
782 // of undoing the substitution.
783 //----------------------------------------------------------------
784 //----------------------------------------------------------------
785 //----------------------------------------------------------------
786 case StackItemType::Reduction:
787 /*
788 * We are moving up the stack.
789 */
790 if (!backtrack) {
791 if (axiom()) {
792 /*
793 * Either you've found a proof or you try a right branch.
794 */
795 if (right_branch_stack.empty())
796 return ProverResult::Valid;
797 else
798 process_axiom_forward();
799 }
800 /*
801 * Backtrack because of depth limiting.
802 */
803 else if (depth_limited() && params::depth_limit_all)
804 reduction_backtrack();
805 /*
806 * Backtrack because there's nothing left to try.
807 */
808 else if (si->actions.empty())
809 reduction_backtrack();
810 /*
811 * There must be something left to try, so try it.
812 */
813 else
814 extend_with_action();
815 }
816 /*
817 * We are moving down the stack.
818 */
819 else {
820 /*
821 * If you're backtracking then you need to jump over axioms.
822 */
823 if (axiom())
824 reduction_backtrack();
825 /*
826 * If you're not at an axiom then you can start going forward
827 * again.
828 */
829 else
830 backtrack = false;
831 }
832 break;
833 //----------------------------------------------------------------
834 //----------------------------------------------------------------
835 //----------------------------------------------------------------
836 // Left branch of Extension. Mostly similar to the Reduction
837 // and Lemmata cases, but the backtrack is again different to
838 // take care of the new variables, the substitution, and the
839 // right_branch_stack.
840 //----------------------------------------------------------------
841 //----------------------------------------------------------------
842 //----------------------------------------------------------------
843 case StackItemType::LeftBranch:
844 /*
845 * Operation is essentially similar to the Reduction and
846 * Lemmata cases. See those for corresponding comments.
847 */
848 if (!backtrack) {
849 if (axiom())
850 process_axiom_forward();
851 else if (depth_limited())
852 left_extension_backtrack();
853 else if (si->actions.empty())
854 left_extension_backtrack();
855 else
856 extend_with_action();
857 }
858 /*
859 * We are moving down the stack.
860 */
861 else {
862 if (axiom())
863 left_extension_backtrack();
864 else
865 backtrack = false;
866 }
867 break;
868 //----------------------------------------------------------------
869 //----------------------------------------------------------------
870 //----------------------------------------------------------------
871 // Right branch of Extension. Mostly similar to the Reduction
872 // and Lemmata cases, but the backtrack is now much more
873 // delicate. See the documentation for right_extension_backtrack.
874 //----------------------------------------------------------------
875 //----------------------------------------------------------------
876 //----------------------------------------------------------------
877 case StackItemType::RightBranch:
878 /*
879 * Operation is essentially similar to the reduction case.
880 */
881 if (!backtrack) {
882 if (axiom()) {
883 if (right_branch_stack.empty())
884 return ProverResult::Valid;
885 else
886 process_axiom_forward();
887 }
888 else if (depth_limited())
889 right_extension_backtrack();
890 else if (si->actions.empty())
891 right_extension_backtrack();
892 else
893 extend_with_action();
894 }
895 /*
896 * We are moving down the stack.
897 */
898 else {
899 if (axiom())
900 right_extension_backtrack();
901 else
902 backtrack = false;
903 }
904 break;
905 //----------------------------------------------------------------
906 default:
907 cerr << "Something is VERY WRONG!" << endl;
908 break;
909 }
910 }
911 return ProverResult::Error;
912}
Interval::tick
bool tick()
Definition Interval.hpp:52
StackProver::process_axiom_forward
void process_axiom_forward()
Start a right branch to continue from an axiom.
Definition StackProver.cpp:516
StackProver::lemmata_backtrack
void lemmata_backtrack()
One of several different kinds of backtracking.
Definition StackProver.cpp:572
StackProver::extend_with_action
void extend_with_action()
Take a single inference (action) and update the stacks accordingly.
Definition StackProver.cpp:358
StackProver::depth_limited
bool depth_limited()
Test for the depth limit.
Definition StackProver.cpp:345
StackProver::left_extension_backtrack
void left_extension_backtrack()
One of several different kinds of backtracking.
Definition StackProver.cpp:576
StackProver::right_branches_started
static uint32_t right_branches_started
We'll be keeping some simple statistics about the search process.
Definition StackProver.hpp:227
StackProver::right_extension_backtrack
void right_extension_backtrack()
One of several different kinds of backtracking.
Definition StackProver.cpp:607
StackProver::reduction_backtrack
void reduction_backtrack()
One of several different kinds of backtracking.
Definition StackProver.cpp:567
StackProver::axiom
bool axiom() const
Test to see if you're at an axiom.
Definition StackProver.cpp:354
cursor_symbols::Cursor::erase_line
static string erase_line(uint8_t n)
Definition cursor.hpp:157
StackItem::item_type
StackItemType item_type
What type of StackItem is this?
Definition StackItem.hpp:55

◆ left_extension_backtrack()

void StackProver::left_extension_backtrack ( )
private

One of several different kinds of backtracking.

Definition at line 576 of file StackProver.cpp.

576 {
577 /*
578 * You're backtracking through a left branch, so you
579 * need to remember to get rid of the corresponding
580 * right branch as well.
581 */
582 right_branch_stack.pop_back();
583 var_index.backtrack();
584 sub_stack.backtrack();
585 backtrack_once();
586}
StackProver::backtrack_once
void backtrack_once()
Basic, single step backtrack on the stack.
Definition StackProver.cpp:560
SubstitutionStack::backtrack
void backtrack()
Remove variables from the stack, and remove substitutions as you go, as far back as the most recent b...
Definition SubstitutionStack.cpp:36
VariableIndex::backtrack
void backtrack()
Backtrack to the last marker.
Definition VariableIndex.cpp:134

◆ lemmata_backtrack()

void StackProver::lemmata_backtrack ( )
private

One of several different kinds of backtracking.

Definition at line 572 of file StackProver.cpp.

572 {
573 backtrack_once();
574}

◆ populate_stack_item()

void StackProver::populate_stack_item ( )
private

Fill the vector of possible actions with everything available.

Definition at line 304 of file StackProver.cpp.

304 {
305 /*
306 * Don't waste your time if the regularity test applies.
307 */
308 if (params::use_regularity_test && !path.test_for_regularity(new_C))
309 return;
310 /*
311 * Don't try to populate axioms.
312 */
313 if (new_C.size() == 0) {
314 return;
315 }
316 /*
317 * NOTE: As these are being stacked, lemmata are actually tried
318 * first.
319 */
320 /*
321 * Extensions
322 */
323 if (params::limit_extensions)
324 matrix.find_limited_extensions(u, si->actions, new_C, var_index, term_index);
325 else
326 matrix.find_all_extensions(u, si->actions, new_C, var_index, term_index);
327 /*
328 * Reductions
329 */
330 if (params::limit_reductions)
331 path.find_limited_reductions(u, si->actions, new_C);
332 else
333 path.find_all_reductions(u, si->actions, new_C);
334 /*
335 * Lemmata
336 */
337 if (params::use_lemmata) {
338 if (params::limit_lemmata)
339 lemmata.find_initial_lemmata(si->actions, new_C);
340 else
341 lemmata.find_all_lemmata(si->actions, new_C);
342 }
343}
Clause::size
size_t size() const
Straightforward get method.
Definition Clause.hpp:78
Lemmata::find_initial_lemmata
void find_initial_lemmata(vector< InferenceItem > &, Clause &)
Find all lemmata that are applicable, but only for the initial Literal in a Clause.
Definition Lemmata.cpp:33
Lemmata::find_all_lemmata
void find_all_lemmata(vector< InferenceItem > &, Clause &)
Find all lemmata that are applicable, given a Clause.
Definition Lemmata.cpp:56
Matrix::find_limited_extensions
void find_limited_extensions(Unifier &, vector< InferenceItem > &, Clause &, VariableIndex &, TermIndex &)
Find all possible extensions given a Clause, but only consider the first Literal in the Clause.
Definition Matrix.cpp:225
Matrix::find_all_extensions
void find_all_extensions(Unifier &, vector< InferenceItem > &, Clause &, VariableIndex &, TermIndex &)
Find all possible extensions given a Clause, considering all Literals in the Clause.
Definition Matrix.cpp:235

◆ problem_has_false_conjecture()

bool StackProver::problem_has_false_conjecture ( ) const
inline

Find out whether the problem's conjecture
is $false.

Definition at line 477 of file StackProver.hpp.

477 {
478 return conjecture_false;
479 }

◆ problem_has_fof_axioms()

bool StackProver::problem_has_fof_axioms ( ) const
inline

Find out from the parser whether the problem had axioms before simplification.

Definition at line 499 of file StackProver.hpp.

499 {
500 return fof_has_axioms;
501 }

◆ problem_has_missing_conjecture()

bool StackProver::problem_has_missing_conjecture ( ) const
inline

Find out whether the problem's conjecture
is missing, in the sense that it didn't appear in the input file.

Definition at line 485 of file StackProver.hpp.

485 {
486 return conjecture_missing;
487 }

◆ problem_has_negated_conjecture_removed()

bool StackProver::problem_has_negated_conjecture_removed ( ) const
inline

Find out whether the problem's
negated conjecture was simplified out.

Definition at line 492 of file StackProver.hpp.

492 {
493 return negated_conjecture_removed;
494 }

◆ problem_has_true_conjecture()

bool StackProver::problem_has_true_conjecture ( ) const
inline

Find out whether the problem's conjecture
is $true.

Definition at line 470 of file StackProver.hpp.

470 {
471 return conjecture_true;
472 }

◆ problem_is_cnf_only()

bool StackProver::problem_is_cnf_only ( ) const
inline

Find out whether the problem is CNF only.

Definition at line 463 of file StackProver.hpp.

463 {
464 return cnf_only;
465 }

◆ process_axiom_forward()

void StackProver::process_axiom_forward ( )
private

Start a right branch to continue from an axiom.

You do this by taking the next available thing from the stack of right branches.

Definition at line 516 of file StackProver.cpp.

516 {
517 /*
518 * When you're moving forward in the search and you hit an axiom,
519 * you need to see whether there are right branches still needing
520 * to be dealt with.
521 *
522 * Note that an empty right_branch_stack - meaning that you've
523 * found a proof - is dealt with by go().
524 *
525 * this_action does not get populated for the new StackItem in
526 * this case.
527 */
528 right_branches_started++;
529 /*
530 * Move the next right branch to the stack.
531 */
532 stack.push_back(right_branch_stack.back());
533 right_branch_stack.pop_back();
534 /*
535 * Reset si.
536 */
537 si = &stack.back();
538 /*
539 * Set up the new state.
540 */
541 new_C = si->c;
542 path = si->p;
543 lemmata = si->l;
544 current_depth = si->depth;
545 /*
546 * We deliberately delayed doing this, so do it now. (See
547 * documentation for StackProver::extend_with_action.)
548 */
549 populate_stack_item();
550 /*
551 * At this point you are starting a right branch, so
552 * if you are restricting backtracking you remove all
553 * alternatives from the relevant point in the stack.
554 */
555 if (params::limit_bt_extensions) {
556 stack[si->bt_restriction_index].restrict_backtrack();
557 }
558}
StackItem::bt_restriction_index
size_t bt_restriction_index
Pointer that allows a right branch to know where to delete alternatives for restricted backtracking.
Definition StackItem.hpp:101

◆ prove()

ProverOutcome StackProver::prove ( )

Here is where the magic happens.

You should only need to load the problem and call this method.

Make sure you deal with reordering.

Definition at line 1049 of file StackProver.cpp.

1049 {
1053 if (params::deterministic_reorder) {
1054 deterministic_reorder(params::number_of_reorders);
1055 }
1056 if (params::random_reorder) {
1057 random_reorder();
1058 }
1059 if (params::random_reorder_literals) {
1060 random_reorder_literals();
1061 }
1062 pair<bool, size_t> start_clause = matrix.find_start();
1063 /*
1064 * If the initial clauses don't have a positive and a negative
1065 * clause then the problem is trivial.
1066 */
1067 if (!start_clause.first) {
1068 return ProverOutcome::False;
1069 }
1070 /*
1071 * Deal with the possible ways to set up start clause(s) according to
1072 * the options. Keep track of which start clauses are in use, and if
1073 * necessary what outcomes for them have been seen so far.
1074 */
1075 set_up_start_clauses();
1076 /*
1077 * Main loop for iterative deepening search.
1078 */
1079 bool switched_to_complete = false;
1080 for (current_depth_limit = params::start_depth;
1081 current_depth_limit <= params::depth_limit;
1082 current_depth_limit += params::depth_increment) {
1083 /*
1084 * See if the parameters dictate that it's time to convert to
1085 * a complete search.
1086 */
1087 if (current_depth_limit >= params::switch_to_complete
1088 && !switched_to_complete) {
1089 params::set_complete_parameters();
1090 /*
1091 * You may have changed some parameters, so make sure all relevant
1092 * start clauses now get tried.
1093 */
1094 set_up_start_clauses();
1095 current_depth_limit = params::start_depth;
1096 switched_to_complete = true;
1097 colour_string::ColourString cs(params::use_colours);
1098 show.nl(1);
1099 show(1, cs("Switching to complete search.").orange(), true);
1100 }
1101 show.nl(1);
1102 show(1, string("SEARCH TO DEPTH: "));
1103 show(1, std::to_string(current_depth_limit), true);
1104 /*
1105 * Generate each possible start move, and try to prove from
1106 * it.
1107 */
1108 size_t start_clause_index = 0;
1109 for (const Clause& C : matrix) {
1110 /*
1111 * Find the next start clause.
1112 */
1113 if (results[start_clause_index] == StartClauseStatus::NoStart
1114 || results[start_clause_index] == StartClauseStatus::False) {
1115 start_clause_index++;
1116 continue;
1117 }
1118 /*
1119 * Reset everything to use the current start clause.
1120 *
1121 * TODO: this is slightly messy at present because
1122 * the var_index doesn't necessarily get reset in the
1123 * most efficient way possible if a previous schedule
1124 * attempt timed out. (You'd need to go back down
1125 * the stack and backtrack it as necessary.) This is
1126 * of course irrelevant
1127 * because it just means you might not get full re-use of
1128 * new variable names, but all the same it would be nice
1129 * to fix.
1130 */
1131 var_index.add_backtrack_point();
1132 new_C = C.make_copy_with_new_vars(var_index, term_index);
1133 reset_for_start();
1134 /*
1135 * Say what's going on.
1136 */
1137 show(1, string("START from clause "));
1138 show(1, std::to_string(start_clause_index + 1));
1139 show(1, string(" of "));
1140 show(1, std::to_string(matrix.get_num_clauses()));
1141 show(2, string(": "));
1142 show(2, new_C.to_string(), true);
1143 cout.flush();
1144 /*
1145 * Set up the initial stack item containing the start clause, and
1146 * populate it.
1147 */
1148 StackItem start_item(StackItemType::Start, new_C, path, lemmata, 1);
1149 start_item.set_this_action(InferenceItem(InferenceItemType::Start, start_clause_index));
1150 stack.push_back(start_item);
1151 si = &stack.back();
1152 populate_stack_item();
1153 /*
1154 * Start with depth 1, as this makes sense when reading output if you're
1155 * using depth of recursion or path length.
1156 */
1157 current_depth = 1;
1158 /*
1159 * Liftoff!!!
1160 */
1161 ProverResult result = go();
1162 /*
1163 * Dealing with the outcome takes some care and depends on
1164 * the parameters being used.
1165 */
1166 switch (result) {
1167 case ProverResult::Valid:
1168 proof_count++;
1169 if (params::build_proof) {
1170 if (params::generate_LaTeX_proof) {
1171 proof_printer.make_LaTeX(params::LaTeX_proof_path,
1172 problem_path,
1173 matrix.make_LaTeX());
1174 }
1175 if (params::generate_Prolog_proof) {
1176 fs::path prolog_path = params::Prolog_proof_path;
1177 proof_printer.make_Prolog(prolog_path);
1178 matrix.write_to_prolog_file(params::Prolog_matrix_path);
1179 }
1180 }
1181 show(1, string(": Found proof number "));
1182 show(1, std::to_string(proof_count), true);
1183 return ProverOutcome::Valid;
1184 break;
1185 case ProverResult::Error:
1186 return ProverOutcome::Error;
1187 break;
1188 case ProverResult::TimeOut:
1189 return ProverOutcome::TimeOut;
1190 break;
1191 case ProverResult::OptionsExhausted:
1192 /*
1193 * If you ran out of options because you reached the depth
1194 * limit then you still need to continue.
1195 */
1196 if (depth_limit_reached) {
1197 show(1, string(": Depth limited"), true);
1198 }
1199 /*
1200 * If you ran out of options without reaching the depth limit, then
1201 * what you do depends on whether or not the search is complete.
1202 */
1203 else {
1204 if (params::search_is_complete()) {
1205 results[start_clause_index] = StartClauseStatus::False;
1206 show(1, string(": False"), true);
1207 }
1208 }
1209 start_clause_index++;
1210 break;
1211 default:
1212 return ProverOutcome::Error;
1213 break;
1214 }
1215 /*
1216 * This is necessary. Yes, I've checked. Think about it: you need
1217 * one extra backtrack to undo the new variables generated when you
1218 * make a start clause.
1219 */
1220 var_index.backtrack();
1221 }
1222 /*
1223 * Loop for start moves ends here.
1224 *
1225 * If everything was False then the theorem is False, otherwise
1226 * at least one attempt was depth-limited.
1227 */
1228 bool all_false = true;
1229 for (StartClauseStatus& outcome : results) {
1230 if (outcome == StartClauseStatus::Start) {
1231 all_false = false;
1232 break;
1233 }
1234 }
1235 if (all_false)
1236 return ProverOutcome::False;
1237 }
1238 /*
1239 * Iterative deepening loop ends here.
1240 */
1241 return ProverOutcome::PathLenLimit;
1242}
Clause::make_copy_with_new_vars
Clause make_copy_with_new_vars(VariableIndex &, TermIndex &) const
Make a copy of an entire clause, introducing new variables.
Definition Clause.cpp:98
Clause::to_string
string to_string(bool=false) const
Convert to a string.
Definition Clause.cpp:202
Matrix::get_num_clauses
ClauseNum get_num_clauses() const
Straightforward get method.
Definition Matrix.hpp:227
Matrix::make_LaTeX
string make_LaTeX(bool=false) const
Make a usable LaTeX representation.
Definition Matrix.cpp:270
Matrix::write_to_prolog_file
void write_to_prolog_file(const path &) const
Write to a file that can be read by Prolog.
Definition Matrix.cpp:283
Matrix::find_start
pair< bool, size_t > find_start() const
Use a simple heuristic to find a good start clause.
Definition Matrix.cpp:51
ProofPrinter::make_Prolog
void make_Prolog(const path &)
Convert to a form suitable for use by the Prolog proof checker and write to a file.
Definition ProofPrinter.cpp:168
ProofPrinter::make_LaTeX
void make_LaTeX(const path &, const path &, const string &)
Convert to LaTeX and store in the specified file.
Definition ProofPrinter.cpp:116
StackProver::reset_for_start
void reset_for_start()
Reset everything so that you can start from a specified start clause.
Definition StackProver.hpp:313
StackProver::random_reorder
void random_reorder()
Randomly reorder the matrix.
Definition StackProver.hpp:436
StackProver::set_up_start_clauses
void set_up_start_clauses()
The start clauses to use depend on the settings, and the settings can change.
Definition StackProver.cpp:922
StackProver::go
ProverResult go()
This runs the proof search from a given Start Move.
Definition StackProver.cpp:669
StackProver::deterministic_reorder
void deterministic_reorder(uint32_t n)
Deterministically reorder the matrix n times.
Definition StackProver.hpp:430
StackProver::random_reorder_literals
void random_reorder_literals()
Randomly reorder the literals in each clause in the matrix.
Definition StackProver.hpp:443
colour_string::ColourString
Simple addition of colour to strings and ostreams.
Definition vic_strings.hpp:118
verbose_print::VPrint::nl
void nl(uint8_t, uint8_t=1)
Definition vic_strings.cpp:140
InferenceItem
Full representation of inferences, beyond just the name.
Definition InferenceItem.hpp:61
params::set_complete_parameters
static void set_complete_parameters()
Change the parameters to make the search complete.
Definition Parameters.cpp:210
params::search_is_complete
static bool search_is_complete()
Self-explanatory.
Definition Parameters.cpp:222

◆ random_reorder()

void StackProver::random_reorder ( )
inline

Randomly reorder the matrix.

Definition at line 436 of file StackProver.hpp.

436 {
437 matrix.random_reorder();
438 }
Matrix::random_reorder
void random_reorder()
Randomly reorder the matrix.
Definition Matrix.cpp:136

◆ random_reorder_literals()

void StackProver::random_reorder_literals ( )
inline

Randomly reorder the literals in each clause in the matrix.

Definition at line 443 of file StackProver.hpp.

443 {
444 matrix.random_reorder_literals();
445 }
Matrix::random_reorder_literals
void random_reorder_literals()
Randomly reorder the literals in each clause in the matrix.
Definition Matrix.cpp:162

◆ read_from_tptp_file()

void StackProver::read_from_tptp_file ( const string & file_name,
bool & found_conjecture,
size_t & fof_size )

Obviously, reads a problem from a TPTP file.

Does pretty much all of the setup required.

Parameters
file_nameName of the file to use.
found_conjectureUsed to indicate whether a conjecture is found in the problem.
fof_sizeNumber of first-order formulas found.

Definition at line 78 of file StackProver.cpp.

80 {
81 TPTPParser parser(&var_index, &fun_index, &term_index, &pred_index, &matrix);
82 parser.parse_tptp_from_file(file_name);
83 status = parser.get_problem_status();
84 bool equality = parser.equality_used();
85 found_conjecture = parser.conjecture_present();
86 fof_size = parser.number_of_fof_formulas();
87 Predicate* equals_predicate = parser.get_equals_predicate();
88 cnf_only = parser.problem_is_cnf_only();
89 conjecture_true = parser.fof_conjecture_is_true();
90 conjecture_false = parser.fof_conjecture_is_false();
91 conjecture_missing = parser.fof_conjecture_is_missing();
92 negated_conjecture_removed = parser.fof_negated_conjecture_removed();
93 fof_has_axioms = parser.fof_has_axioms();
94 simplified_fof_has_axioms = parser.simplified_fof_has_axioms();
95 tptp_conversion_string = parser.get_tptp_conversion_string();
96 parser.clear();
97 num_preds = pred_index.get_num_preds();
98 /*
99 * num_preds for Matrix is set by parser.
100 */
101 path.set_num_preds(num_preds);
102
103 if (params::show_clauses) {
104 std::exit(EXIT_SUCCESS);
105 }
106
107 if (status != string("") && params::first_parse) {
108 show(1, string("Problem status found: "));
109 show(1, status, true);
110 }
111 if (equality && params::add_equality_axioms) {
112 if (params::first_parse) {
113 show(1, string("Problem involves equality: adding axioms for =."), true);
114 params::first_parse = false;
115 }
116 add_equality_axioms(equals_predicate);
117 if (params::equality_axioms_at_start) {
118 matrix.move_equals_to_start();
119 }
120 }
121 /*
122 * Any further variables will be anonymous.
123 */
124 var_index.set_all_names_added();
125 }
Matrix::move_equals_to_start
void move_equals_to_start()
Self-explanatory.
Definition Matrix.cpp:183
StackProver::add_equality_axioms
void add_equality_axioms(Predicate *)
After reading a problem in which = and/or != appears, add the axioms for equality.
Definition StackProver.cpp:127
TPTPParser
Wrap up everything the TPTP parser needs to do inside a single class.
Definition TPTPParser.hpp:658
VariableIndex::set_all_names_added
void set_all_names_added()
Call this to indicate that only anonymous variables can now be created.
Definition VariableIndex.cpp:63

◆ reduction_backtrack()

void StackProver::reduction_backtrack ( )
private

One of several different kinds of backtracking.

Definition at line 567 of file StackProver.cpp.

567 {
568 sub_stack.backtrack();
569 backtrack_once();
570}

◆ reset_for_start()

void StackProver::reset_for_start ( )
inlineprivate

Reset everything so that you can start from a specified start clause.

Definition at line 313 of file StackProver.hpp.

313 {
314 depth_limit_reached = false;
315 si = nullptr;
316 backtrack = false;
317 path.clear();
318 stack.clear();
319 lemmata.clear();
320 right_branch_stack.clear();
321 sub_stack.clear();
322 }
Lemmata::clear
void clear()
Self-explanatory.
Definition Lemmata.hpp:70
SubstitutionStack::clear
void clear()
Reset everything.
Definition SubstitutionStack.hpp:91
StackItem::clear
void clear()
Delete all the remaining possible actions.
Definition StackItem.hpp:208

◆ right_extension_backtrack()

void StackProver::right_extension_backtrack ( )
private

One of several different kinds of backtracking.

Here be DRAGONS.

Care needed here. If the state is a right branch, then it may or may not have to go back on right_branch_stack as you may or may not need to try it again, depending on the settings.

If you get this wrong you get a REALLY evil bug, because with the standard restricted backtracking you put it back on the stack when it's not needed. You then end up with extra things in the proof certificate which invalidate it, even though you can take them out and possibly get something valid.

Guess how I know this!

TODO: when I implement params::hard_prune it needs to be considered here.

Definition at line 607 of file StackProver.cpp.

607 {
608 /*
609 * If you're not limiting backtracking for extensions, or
610 * you *are*, but you're still exploring left trees, then this
611 * is straightforward: just put the item back on right_branch_stack
612 * so that it gets explored again later.
613 */
614 if (!params::limit_bt_extensions ||
615 ((params::limit_bt_extensions || params::limit_bt_all) &&
616 !params::limit_bt_extensions_left_tree)) {
617 /*
618 * Why is this necessary? After we backtrack we may make different
619 * substitutions, so in revisiting the right branch different
620 * possibilties may apply, so we re-compute them later.
621 */
622 stack.back().clear();
623 right_branch_stack.push_back(stack.back());
624 backtrack_once();
625 return;
626 }
627 /*
628 * We know we are limiting backtracking for extensions, and we
629 * are not exploring the left tree.
630 *
631 * Care is needed if you're not backtracking within the left
632 * part of the tree. You need to move back down the stack,
633 * deleting everything while also making sure that sub_stack
634 * and var_index are correctly maintained. Also, you don't
635 * want to return anything to right_branch_stack.
636 *
637 * This goes back to where the relevant literal was selected.
638 * Thus if you are not limiting the possibilities to only those
639 * for the first literal, it's open to the backtracking
640 * restriction to leave other possibilites to be tried, and
641 * they get picked up from this point.
642 */
643 if (params::limit_bt_extensions_left_tree) {
644 size_t target_index = si->bt_restriction_index;
645 size_t current_index = stack.size() - 1;
646 while (current_index > target_index) {
647 switch (si->item_type) {
648 case StackItemType::Lemmata:
649 break;
650 case StackItemType::Reduction:
651 sub_stack.backtrack();
652 break;
653 case StackItemType::LeftBranch:
654 var_index.backtrack();
655 sub_stack.backtrack();
656 break;
657 case StackItemType::RightBranch:
658 break;
659 default:
660 cerr << "Something is VERY WRONG!" << endl;
661 break;
662 }
663 backtrack_once();
664 current_index--;
665 }
666 }
667}

◆ set_num_preds()

void StackProver::set_num_preds ( size_t n)

Set the number of predicates.

But don't! You should never need to do this.

Definition at line 72 of file StackProver.cpp.

72 {
73 num_preds = n;
74 matrix.set_num_preds(n);
75 path.set_num_preds(n);
76}
Matrix::set_num_preds
void set_num_preds(size_t)
Make an empty index.
Definition Matrix.cpp:42

◆ set_problem_path()

void StackProver::set_problem_path ( fs::path & p)
inline

Set the path for the problem being solved. U.

Used only to produce nice output.

Definition at line 397 of file StackProver.hpp.

397{ problem_path = p; }

◆ set_timeout()

void StackProver::set_timeout ( chrono::steady_clock::time_point time)
inline

Set a timeout.

A StackProver is always constructed to have no timeout. This sets a timeout to use in seconds. The parameters are separate from the params::???? values as the latter apply globally whereas these allow for schedules to be constructed.

Parameters
timethe time to stop: you will need to know about the standard library!

Definition at line 388 of file StackProver.hpp.

388 {
389 use_timeout = true;
390 end_time = time;
391 }

◆ set_up_start_clauses()

void StackProver::set_up_start_clauses ( )
private

The start clauses to use depend on the settings, and the settings can change.

Definition at line 922 of file StackProver.cpp.

922 {
923 results.clear();
924 size_t m_size = matrix.get_num_clauses();
925 /*
926 * Make sure noone has messed up and not set any start
927 * clause optionss.
928 */
929 if (params::no_start_options())
930 params::correct_missing_start_options();
931 /*
932 * The allstart option overides everything else so this is easy.
933 */
934 if (params::all_start) {
935 for (size_t i = 0; i < m_size; i++) {
936 results.push_back(StartClauseStatus::Start);
937 }
938 return;
939 }
940 bool first_clause_included = false;
941 /*
942 * params::all_pos_neg_start indicates use of positive
943 * or negative start clauses according to the representation.
944 * When you don't also have conjecture_start, either include
945 * all, or just the first possibility found.
946 */
947 if (params::all_pos_neg_start && !params::conjecture_start) {
948 for (size_t i = 0; i < m_size; i++) {
949 if (
950 (
951 (params::positive_representation && matrix.is_positive(i))
952 ||
953 (!params::positive_representation && matrix.is_negative(i))
954 )
955 &&
956 (!(params::restrict_start && first_clause_included))
957 ) {
958 results.push_back(StartClauseStatus::Start);
959 first_clause_included = true;
960 }
961 else {
962 results.push_back(StartClauseStatus::NoStart);
963 }
964 }
965 }
966 /*
967 * Similar case if you have conjecture_start but not all_pos_neg_start.
968 */
969 else if (!params::all_pos_neg_start && params::conjecture_start) {
970 for (size_t i = 0; i < m_size; i++) {
971 if (matrix.is_conjecture(i)
972 &&
973 (!(params::restrict_start && first_clause_included))) {
974 results.push_back(StartClauseStatus::Start);
975 first_clause_included = true;
976 }
977 else {
978 results.push_back(StartClauseStatus::NoStart);
979 }
980 }
981 }
982 /*
983 * The tricky case is when you want to combine pos/neg clauses,
984 * conjecture clauses, and restriction in some other way.
985 *
986 * Assume here that you have all_pos_neg_start and conjecture_start.
987 */
988 else {
989 for (size_t i = 0; i < m_size; i++) {
990 if (matrix.is_conjecture(i)
991 &&
992 (
993 (params::positive_representation && matrix.is_positive(i))
994 ||
995 (!params::positive_representation && matrix.is_negative(i))
996 )
997 &&
998 !(params::restrict_start && first_clause_included)) {
999 results.push_back(StartClauseStatus::Start);
1000 first_clause_included = true;
1001 }
1002 else {
1003 results.push_back(StartClauseStatus::NoStart);
1004 }
1005 }
1006 }
1007 /*
1008 * There's a rare possibility that---because either there was no
1009 * (negated) conjecture clause in the problem, or they were
1010 * simplified out---at this point no start clause has been
1011 * selected. If that's the case, either use all positive/negative
1012 * clauses or just the first, according to the parameters set.
1013 *
1014 * Note: this must choose at least one start clause because problems
1015 * without a positive and negative clause have already been solved.
1016 */
1017 if (!first_clause_included) {
1018 if (params::verbosity > 2) {
1019 cout << "Note: you're asking for a conjecture to start, but there are none!" << endl;
1020 cout << " depending on the other parameter settings, we will use one or " << endl;
1021 cout << " all of the negative clauses." << endl;
1022 }
1023 // Don't forget this! If you get here you have a whole bunch of
1024 // NoStart in results!
1025 results.clear();
1026 for (size_t i = 0; i < m_size; i++) {
1027 if ((
1028 (params::positive_representation && matrix.is_positive(i))
1029 ||
1030 (!params::positive_representation && matrix.is_negative(i))
1031 ) &&
1032 !(params::restrict_start && first_clause_included)) {
1033 results.push_back(StartClauseStatus::Start);
1034 first_clause_included = true;
1035 }
1036 else {
1037 results.push_back(StartClauseStatus::NoStart);
1038 }
1039 }
1040 }
1041}
Matrix::is_negative
bool is_negative(size_t i) const
Is a particular Clause negative?.
Definition Matrix.hpp:247
Matrix::is_conjecture
bool is_conjecture(size_t i) const
Is a particular Clause a conjecture?
Definition Matrix.cpp:46
Matrix::is_positive
bool is_positive(size_t i) const
Is a particular Clause positive?.
Definition Matrix.hpp:241
params::no_start_options
static bool no_start_options()
Self-explanatory.
Definition Parameters.cpp:242
params::correct_missing_start_options
static void correct_missing_start_options()
Self-explanatory.
Definition Parameters.cpp:249

◆ show_matrix() [1/2]

void StackProver::show_matrix ( )
inline

Show a nicely formatted matrix.

Definition at line 449 of file StackProver.hpp.

449 {
450 cout << "Matrix:" << endl;
451 cout << matrix.to_string() << endl;
452 }
Matrix::to_string
string to_string() const
Make a string representation.
Definition Matrix.cpp:247

◆ show_matrix() [2/2]

void StackProver::show_matrix ( ) const
inline

Definition at line 541 of file StackProver.hpp.

541{ cout << matrix << endl; }

◆ show_path()

void StackProver::show_path ( ) const
inline

Definition at line 542 of file StackProver.hpp.

542{ cout << path << endl; }

◆ show_right_stack()

void StackProver::show_right_stack ( )

Definition at line 1258 of file StackProver.cpp.

1258 {
1259 cout << "--------------------------------------------------------" << endl;
1260 cout << "Right Stack:" << endl;
1261 cout << "--------------------------------------------------------" << endl;
1262 for (auto s : right_branch_stack) {
1263 cout << s << endl;
1264 }
1265 cout << "--------------------------------------------------------" << endl;
1266}

◆ show_stack()

void StackProver::show_stack ( )

Definition at line 1248 of file StackProver.cpp.

1248 {
1249 cout << "--------------------------------------------------------" << endl;
1250 cout << "Stack:" << endl;
1251 cout << "--------------------------------------------------------" << endl;
1252 for (auto s : stack) {
1253 cout << s << endl;
1254 }
1255 cout << "--------------------------------------------------------" << endl;
1256}

◆ show_statistics()

void StackProver::show_statistics ( ) const

Display counts of number of extensions tried and so on.

Definition at line 1268 of file StackProver.cpp.

1268 {
1269 verbose_print::VPrint show(params::verbosity);
1270 show(1, string("Reductions: "));
1271 show(1, std::to_string(reductions_tried));
1272 show(1, string(" Extensions: "));
1273 show(1, std::to_string(extensions_tried));
1274 show(1, string(" Lemmata: "));
1275 show(1, std::to_string(lemmata_tried));
1276 show(1, string(" Right branches: "));
1277 show(1, std::to_string(right_branches_started), true);
1278}
verbose_print::VPrint
Definition vic_strings.hpp:237

◆ show_term_index()

void StackProver::show_term_index ( )
inline

Definition at line 545 of file StackProver.hpp.

545{ cout << term_index << endl; }

◆ show_tptp_proof()

void StackProver::show_tptp_proof ( )
inline

Show a Prolog-formatted proof.

Definition at line 515 of file StackProver.hpp.

515 {
516 cout << endl << "% Problem matrix:" << endl;
517 matrix.show_tptp();
518 cout << endl << "% Proof stack:" << endl;
519 proof_printer.show_tptp();
520 }
Matrix::show_tptp
void show_tptp() const
Output in TPTP compatible format.
Definition Matrix.cpp:300
ProofPrinter::show_tptp
void show_tptp()
Show the proof in a TPTP-friendly format.
Definition ProofPrinter.cpp:282

◆ simplified_problem_has_fof_axioms()

bool StackProver::simplified_problem_has_fof_axioms ( ) const
inline

Find out from the parser whether the problem had axioms after simplification.

Definition at line 506 of file StackProver.hpp.

506 {
507 return simplified_fof_has_axioms;
508 }

Friends And Related Symbol Documentation

◆ operator<<

ostream & operator<< ( ostream & out,
const StackProver & p )
friend

Definition at line 1280 of file StackProver.cpp.

1280 {
1281 out << "Current state of the RecursiveProver object" << endl;
1282 out << "-------------------------------------------" << endl << endl;
1283 out << p.var_index << endl;
1284 out << p.fun_index << endl;
1285 out << p.term_index << endl;
1286 out << p.path << endl;
1287 out << p.matrix << endl;
1288 return out;
1289}

Member Data Documentation

◆ action

InferenceItem StackProver::action
private

Stores the next action from the current StackItem.

Definition at line 146 of file StackProver.hpp.

◆ backtrack

bool StackProver::backtrack
private

Are we moving up or down the stack?

Definition at line 191 of file StackProver.hpp.

◆ cnf_only

bool StackProver::cnf_only
private

Keep track of whether there were any FOF formulas in the problem file.

Definition at line 327 of file StackProver.hpp.

◆ conjecture_false

bool StackProver::conjecture_false
private

Keep track of whether the parser found the conjecture to be false.

Definition at line 335 of file StackProver.hpp.

◆ conjecture_missing

bool StackProver::conjecture_missing
private

Keep track of whether the parser found a conjecture in the problem file.

Definition at line 339 of file StackProver.hpp.

◆ conjecture_true

bool StackProver::conjecture_true
private

Keep track of whether the parser found the conjecture to be true.

Definition at line 331 of file StackProver.hpp.

◆ current_depth

uint32_t StackProver::current_depth
private

Self-explanatary.

Definition at line 164 of file StackProver.hpp.

◆ current_depth_limit

uint32_t StackProver::current_depth_limit
private

Self-explanatary.

Definition at line 160 of file StackProver.hpp.

◆ depth_limit_reached

bool StackProver::depth_limit_reached
private

Self-explanatary.

Definition at line 168 of file StackProver.hpp.

◆ end_time

chrono::steady_clock::time_point StackProver::end_time
private

When do we stop because of a timeout?

Definition at line 240 of file StackProver.hpp.

◆ extensions_tried

uint32_t StackProver::extensions_tried = 0
staticprivate

We'll be keeping some simple statistics about the search process.

Definition at line 217 of file StackProver.hpp.

◆ fof_has_axioms

bool StackProver::fof_has_axioms
private

Keep track of whether the parser found that it's an FOF problem with axioms before simplification.

Definition at line 348 of file StackProver.hpp.

◆ fun_index

FunctionIndex StackProver::fun_index
private

This class needs one of each kind of index to keep track of Variables, Terms etc.

Definition at line 90 of file StackProver.hpp.

◆ lemmata

Lemmata StackProver::lemmata
private

At any point in the search process this is a copy of the list of lemmata for the current node in the proof being constructed.

Definition at line 138 of file StackProver.hpp.

◆ lemmata_tried

uint32_t StackProver::lemmata_tried = 0
staticprivate

We'll be keeping some simple statistics about the search process.

Definition at line 222 of file StackProver.hpp.

◆ matrix

Matrix StackProver::matrix
private

A copy of the matrix you're working with.

Definition at line 120 of file StackProver.hpp.

◆ negated_conjecture_removed

bool StackProver::negated_conjecture_removed
private

Keep track of whether the parser simplified the conjecture away.

Definition at line 343 of file StackProver.hpp.

◆ new_C

Clause StackProver::new_C
private

At any point in the search process this is a copy of the clause for the current node in the proof being constructed.

Definition at line 132 of file StackProver.hpp.

◆ num_preds

size_t StackProver::num_preds
private

How many prdicates does the problem of interest have?

Definition at line 80 of file StackProver.hpp.

◆ output_interval

Interval StackProver::output_interval
private

How often do you output updates about progress?

Definition at line 204 of file StackProver.hpp.

◆ path

SimplePath StackProver::path
private

At any point in the search process this is a copy of the path for the current node in the proof being constructed.

Definition at line 126 of file StackProver.hpp.

◆ pred_index

PredicateIndex StackProver::pred_index
private

This class needs one of each kind of index to keep track of Variables, Terms etc.

Definition at line 100 of file StackProver.hpp.

◆ problem_path

fs::path StackProver::problem_path
private

Path for the problem of interest.

Definition at line 200 of file StackProver.hpp.

◆ proof_count

uint32_t StackProver::proof_count
private

If we're searching for multiple proofs, keep count
of which one this is.

Definition at line 232 of file StackProver.hpp.

◆ proof_printer

ProofPrinter StackProver::proof_printer
private

You need one of these to print LaTeX output or any kind of proof certificate.

Definition at line 196 of file StackProver.hpp.

◆ reductions_tried

uint32_t StackProver::reductions_tried = 0
staticprivate

We'll be keeping some simple statistics about the search process.

Note that at present these statistics include everything tried over all steps in a schedule.

Definition at line 212 of file StackProver.hpp.

◆ results

vector<StartClauseStatus> StackProver::results
private

This is populated by the StackProver::set_up_start_clauses method.

That method looks at the settings for start clauses and tries to achieve them all in a sensible way. Initially this indicates which clauses to use to start, but then stores the results obtained after trying each possibility.

Definition at line 116 of file StackProver.hpp.

◆ right_branch_stack

vector<StackItem> StackProver::right_branch_stack
private

We build the proof by trying the left branches of extensions first: this stack keeps track of the right branches that we need to come back to.

Definition at line 187 of file StackProver.hpp.

◆ right_branches_started

uint32_t StackProver::right_branches_started = 0
staticprivate

We'll be keeping some simple statistics about the search process.

Definition at line 227 of file StackProver.hpp.

◆ show

verbose_print::VPrint StackProver::show
private

Set up printing according to verbosity.

Definition at line 244 of file StackProver.hpp.

◆ si

StackItem* StackProver::si
private

Pointer to the current StackItem.

Be very careful with this. At present its use is fine because I don't think that the stack gets modified while the pointer is in use. BUT it may be a good future modification to make this an index rather than a pointer in case we run into trouble with the vector class moving things in memory.

Definition at line 156 of file StackProver.hpp.

◆ simplified_fof_has_axioms

bool StackProver::simplified_fof_has_axioms
private

Keep track of whether the parser found that it's an FOF problem with axioms after simplification.

Definition at line 353 of file StackProver.hpp.

◆ stack

vector<StackItem> StackProver::stack
private

Main stack: this is constructed by the search process and, if completed, represents a proof.

Definition at line 181 of file StackProver.hpp.

◆ status

string StackProver::status
private

Problem status, if found in input file.

Definition at line 172 of file StackProver.hpp.

◆ sub_stack

SubstitutionStack StackProver::sub_stack
private

There is a separate stack to make application and removal of substitutions straightforward.

Definition at line 105 of file StackProver.hpp.

◆ term_index

TermIndex StackProver::term_index
private

This class needs one of each kind of index to keep track of Variables, Terms etc.

Definition at line 95 of file StackProver.hpp.

◆ tptp_conversion_string

string StackProver::tptp_conversion_string
private

TPTP-friendly description of the clause conversion.

Definition at line 176 of file StackProver.hpp.

◆ u

Unifier StackProver::u
private

We need a single Unifier to use throught the process.

Definition at line 142 of file StackProver.hpp.

◆ use_timeout

bool StackProver::use_timeout
private

Are we using a timeout?

Definition at line 236 of file StackProver.hpp.

◆ var_index

VariableIndex StackProver::var_index
private

This class needs one of each kind of index to keep track of Variables, Terms etc.

Definition at line 85 of file StackProver.hpp.

The documentation for this class was generated from the following files: