Theory Mono_Nits

(*  Title:      HOL/Nitpick_Examples/Mono_Nits.thy
    Author:     Jasmin Blanchette, TU Muenchen
    Copyright   2009-2011

Examples featuring Nitpick's monotonicity check.
*)

section ‹Examples Featuring Nitpick's Monotonicity Check›

theory Mono_Nits
imports Main
        (* "~/afp/thys/DPT-SAT-Solver/DPT_SAT_Solver" *)
        (* "~/afp/thys/AVL-Trees/AVL2" "~/afp/thys/Huffman/Huffman" *)
begin

ML ‹
open Nitpick_Util
open Nitpick_HOL
open Nitpick_Preproc

exception BUG

val thy = \<^theory>
val ctxt = \<^context>
val subst = []
val tac_timeout = seconds 1.0
val case_names = case_const_names ctxt
val defs = all_defs_of thy subst
val nondefs = all_nondefs_of ctxt subst
val def_tables = const_def_tables ctxt subst defs
val nondef_table = const_nondef_table nondefs
val simp_table = Unsynchronized.ref (const_simp_table ctxt subst)
val psimp_table = const_psimp_table ctxt subst
val choice_spec_table = const_choice_spec_table ctxt subst
val intro_table = inductive_intro_table ctxt subst def_tables
val ground_thm_table = ground_theorem_table thy
val ersatz_table = ersatz_table ctxt
val hol_ctxt as {thy, ...} : hol_context =
  {thy = thy, ctxt = ctxt, max_bisim_depth = ~1, boxes = [], wfs = [],
   user_axioms = NONE, debug = false, whacks = [], binary_ints = SOME false,
   destroy_constrs = true, specialize = false, star_linear_preds = false,
   total_consts = NONE, needs = NONE, tac_timeout = tac_timeout, evals = [],
   case_names = case_names, def_tables = def_tables,
   nondef_table = nondef_table, nondefs = nondefs, simp_table = simp_table,
   psimp_table = psimp_table, choice_spec_table = choice_spec_table,
   intro_table = intro_table, ground_thm_table = ground_thm_table,
   ersatz_table = ersatz_table, skolems = Unsynchronized.ref [],
   special_funs = Unsynchronized.ref [], unrolled_preds = Unsynchronized.ref [],
   wf_cache = Unsynchronized.ref [], constr_cache = Unsynchronized.ref []}
val binarize = false

fun is_mono t =
  Nitpick_Mono.formulas_monotonic hol_ctxt binarize \<^typ>‹'a› ([t], [])

fun is_const t =
  let val T = fastype_of t in
    Logic.mk_implies (Logic.mk_equals (Free ("dummyP", T), t), \<^Const>‹False›)
    |> is_mono
  end

fun mono t = is_mono t orelse raise BUG
fun nonmono t = not (is_mono t) orelse raise BUG
fun const t = is_const t orelse raise BUG
fun nonconst t = not (is_const t) orelse raise BUG
›

ML ‹Nitpick_Mono.trace := false›

ML_val ‹const \<^term>‹A::('a⇒'b)››
ML_val ‹const \<^term>‹(A::'a set) = A››
ML_val ‹const \<^term>‹(A::'a set set) = A››
ML_val ‹const \<^term>‹(λx::'a set. a ∈ x)››
ML_val ‹const \<^term>‹{{a::'a}} = C››
ML_val ‹const \<^term>‹{f::'a⇒nat} = {g::'a⇒nat}››
ML_val ‹const \<^term>‹A ∪ (B::'a set)››
ML_val ‹const \<^term>‹λA B x::'a. A x ∨ B x››
ML_val ‹const \<^term>‹P (a::'a)››
ML_val ‹const \<^term>‹λa::'a. b (c (d::'a)) (e::'a) (f::'a)››
ML_val ‹const \<^term>‹∀A::'a set. a ∈ A››
ML_val ‹const \<^term>‹∀A::'a set. P A››
ML_val ‹const \<^term>‹P ∨ Q››
ML_val ‹const \<^term>‹A ∪ B = (C::'a set)››
ML_val ‹const \<^term>‹(λA B x::'a. A x ∨ B x) A B = C››
ML_val ‹const \<^term>‹(if P then (A::'a set) else B) = C››
ML_val ‹const \<^term>‹let A = (C::'a set) in A ∪ B››
ML_val ‹const \<^term>‹THE x::'b. P x››
ML_val ‹const \<^term>‹(λx::'a. False)››
ML_val ‹const \<^term>‹(λx::'a. True)››
ML_val ‹const \<^term>‹(λx::'a. False) = (λx::'a. False)››
ML_val ‹const \<^term>‹(λx::'a. True) = (λx::'a. True)››
ML_val ‹const \<^term>‹Let (a::'a) A››
ML_val ‹const \<^term>‹A (a::'a)››
ML_val ‹const \<^term>‹insert (a::'a) A = B››
ML_val ‹const \<^term>‹- (A::'a set)››
ML_val ‹const \<^term>‹finite (A::'a set)››
ML_val ‹const \<^term>‹¬ finite (A::'a set)››
ML_val ‹const \<^term>‹finite (A::'a set set)››
ML_val ‹const \<^term>‹λa::'a. A a ∧ ¬ B a››
ML_val ‹const \<^term>‹A < (B::'a set)››
ML_val ‹const \<^term>‹A ≤ (B::'a set)››
ML_val ‹const \<^term>‹[a::'a]››
ML_val ‹const \<^term>‹[a::'a set]››
ML_val ‹const \<^term>‹[A ∪ (B::'a set)]››
ML_val ‹const \<^term>‹[A ∪ (B::'a set)] = [C]››
ML_val ‹const \<^term>‹{(λx::'a. x = a)} = C››
ML_val ‹const \<^term>‹(λa::'a. ¬ A a) = B››
ML_val ‹const \<^prop>‹∀F f g (h::'a set). F f ∧ F g ∧ ¬ f a ∧ g a ⟶ ¬ f a››
ML_val ‹const \<^term>‹λA B x::'a. A x ∧ B x ∧ A = B››
ML_val ‹const \<^term>‹p = (λ(x::'a) (y::'a). P x ∨ ¬ Q y)››
ML_val ‹const \<^term>‹p = (λ(x::'a) (y::'a). p x y :: bool)››
ML_val ‹const \<^term>‹p = (λA B x. A x ∧ ¬ B x) (λx. True) (λy. x ≠ y)››
ML_val ‹const \<^term>‹p = (λy. x ≠ y)››
ML_val ‹const \<^term>‹(λx. (p::'a⇒bool⇒bool) x False)››
ML_val ‹const \<^term>‹(λx y. (p::'a⇒'a⇒bool⇒bool) x y False)››
ML_val ‹const \<^term>‹f = (λx::'a. P x ⟶ Q x)››
ML_val ‹const \<^term>‹∀a::'a. P a››

ML_val ‹nonconst \<^term>‹∀P (a::'a). P a››
ML_val ‹nonconst \<^term>‹THE x::'a. P x››
ML_val ‹nonconst \<^term>‹SOME x::'a. P x››
ML_val ‹nonconst \<^term>‹(λA B x::'a. A x ∨ B x) = myunion››
ML_val ‹nonconst \<^term>‹(λx::'a. False) = (λx::'a. True)››
ML_val ‹nonconst \<^prop>‹∀F f g (h::'a set). F f ∧ F g ∧ ¬ a ∈ f ∧ a ∈ g ⟶ F h››

ML_val ‹mono \<^prop>‹Q (∀x::'a set. P x)››
ML_val ‹mono \<^prop>‹P (a::'a)››
ML_val ‹mono \<^prop>‹{a} = {b::'a}››
ML_val ‹mono \<^prop>‹(λx. x = a) = (λy. y = (b::'a))››
ML_val ‹mono \<^prop>‹(a::'a) ∈ P ∧ P ∪ P = P››
ML_val ‹mono \<^prop>‹∀F::'a set set. P››
ML_val ‹mono \<^prop>‹¬ (∀F f g (h::'a set). F f ∧ F g ∧ ¬ a ∈ f ∧ a ∈ g ⟶ F h)››
ML_val ‹mono \<^prop>‹¬ Q (∀x::'a set. P x)››
ML_val ‹mono \<^prop>‹¬ (∀x::'a. P x)››
ML_val ‹mono \<^prop>‹myall P = (P = (λx::'a. True))››
ML_val ‹mono \<^prop>‹myall P = (P = (λx::'a. False))››
ML_val ‹mono \<^prop>‹∀x::'a. P x››
ML_val ‹mono \<^term>‹(λA B x::'a. A x ∨ B x) ≠ myunion››

ML_val ‹nonmono \<^prop>‹A = (λx::'a. True) ∧ A = (λx. False)››
ML_val ‹nonmono \<^prop>‹∀F f g (h::'a set). F f ∧ F g ∧ ¬ a ∈ f ∧ a ∈ g ⟶ F h››

ML ‹
val preproc_timeout = seconds 5.0
val mono_timeout = seconds 1.0

fun is_forbidden_theorem name =
  Long_Name.count name <> 2 orelse
  String.isPrefix "type_definition" (List.last (Long_Name.explode name)) orelse
  String.isPrefix "arity_" (List.last (Long_Name.explode name)) orelse
  String.isSuffix "_def" name orelse
  String.isSuffix "_raw" name

fun theorems_of thy =
  filter (fn (name, th) =>
             not (is_forbidden_theorem name) andalso
             Thm.theory_long_name th = Context.theory_long_name thy)
         (Global_Theory.all_thms_of thy true)

fun check_formulas tsp =
  let
    fun is_type_actually_monotonic T =
      Nitpick_Mono.formulas_monotonic hol_ctxt binarize T tsp
    val free_Ts = fold Term.add_tfrees ((op @) tsp) [] |> map TFree
    val (mono_free_Ts, nonmono_free_Ts) =
      Timeout.apply mono_timeout
          (List.partition is_type_actually_monotonic) free_Ts
  in
    if not (null mono_free_Ts) then "MONO"
    else if not (null nonmono_free_Ts) then "NONMONO"
    else "NIX"
  end
  handle Timeout.TIMEOUT _ => "TIMEOUT"
       | NOT_SUPPORTED _ => "UNSUP"
       | exn => if Exn.is_interrupt exn then Exn.reraise exn else "UNKNOWN"

fun check_theory thy =
  let
    val path = File.tmp_path (Context.theory_base_name thy ^ ".out" |> Path.explode)
    val _ = File.write path ""
    fun check_theorem (name, th) =
      let
        val t = th |> Thm.prop_of |> Type.legacy_freeze |> close_form
        val neg_t = Logic.mk_implies (t, \<^prop>‹False›)
        val (nondef_ts, def_ts, _, _, _, _) =
          Timeout.apply preproc_timeout (preprocess_formulas hol_ctxt [])
                              neg_t
        val res = name ^ ": " ^ check_formulas (nondef_ts, def_ts)
      in File.append path (res ^ "\n"); writeln res end
      handle Timeout.TIMEOUT _ => ()
  in thy |> theorems_of |> List.app check_theorem end
›

(*
ML_val {* check_theory @{theory AVL2} *}
ML_val {* check_theory @{theory Fun} *}
ML_val {* check_theory @{theory Huffman} *}
ML_val {* check_theory @{theory List} *}
ML_val {* check_theory @{theory Map} *}
ML_val {* check_theory @{theory Relation} *}
*)

end