AP_TERM_TACTactic.AP_TERM_TAC : tactic
Strips a function application from both sides of an equational goal.
AP_TERM_TAC reduces a goal of the form
A ?- f x = f y by stripping away the function applications,
giving the new goal A ?- x = y.
A ?- f x = f y
================ AP_TERM_TAC
A ?- x = y
Fails unless the goal is equational, with both sides being applications of the same function.
Thm.AP_TERM, Thm.AP_THM, Tactic.AP_THM_TAC, Tactic.MK_COMB_TAC, Tactic.ABS_TAC