Tactic.FULL_STRUCT_CASES

STRUCTURE

SYNOPSIS

A form of STRUCT_CASES_TAC that also applies the case analysis to the assumption list.

DESCRIPTION

See STRUCT_CASES_TAC.

FAILURE

Fails unless provided with a theorem that is a conjunction of (possibly multiply existentially quantified) terms which assert the equality of a variable with some given terms.

EXAMPLE

Suppose we have the goal:

  ~(l:(*)list = []) ?- (LENGTH l) > 0

then we can get rid of the universal quantifier from the inbuilt list theorem list_CASES:

   list_CASES = !l. (l = []) \/ (?t h. l = CONS h t)

and then use FULL_STRUCT_CASES_TAC. This amounts to applying the following tactic:

   FULL_STRUCT_CASES_TAC (SPEC_ALL list_CASES)

which results in the following two subgoals:

   ~(CONS h t = []) ?- (LENGTH(CONS h t)) > 0

   ~([] = []) ?- (LENGTH[]) > 0

Note that this is a rather simple case, since there are no constraints, and therefore the resulting subgoals have no extra assumptions.

USES

Generating a case split from the axioms specifying a structure.

SEEALSO

ASM_CASES_TAC, BOOL_CASES_TAC, COND_CASES_TAC, DISJ_CASES_TAC, STRUCT_CASES_TAC