new_open_axiom : (string * term) -> thm

SYNOPSIS
Sets up a new axiom in the current theory.

DESCRIBE
If tm is a term of type bool, a call new_open_axiom("name",tm) creates a theorem
   |- tm
and stores it away in the current theory.

FAILURE
Fails if HOL is not in draft mode, or there is already an axiom or definition of that name in the current theory, or it the given term does not have type bool.

EXAMPLE
  - new_theory "gurk";
  () : unit

  - new_axiom("untrue",--`x = 1`--));
  |- x = 1

COMMENTS
For most purposes, it is unnecessary to declare new axioms: all of classical mathematics can be derived by definitional extension alone. Proceeding by definition is not only more elegant, but also guarantees the consistency of the deductions made. However, there are certain entities which cannot be modelled in simple type theory without further axioms, such as higher transfinite ordinals.

SEEALSO  mk_thm,   new_definition

HOL  Kananaskis 0