\DOC AP_THM_TAC

\TYPE {AP_THM_TAC : tactic}

\SYNOPSIS
Strips identical operands from functions on both sides of an equation.

\KEYWORDS
tactic.

\DESCRIBE
When applied to a goal of the form {A ?- f x = g x}, the tactic {AP_THM_TAC}
strips away the operands of the function application:
{
    A ?- f x = g x
   ================  AP_THM_TAC
      A ?- f = g
}

\FAILURE
Fails unless the goal has the above form, namely an equation both sides of
which consist of function applications to the same argument.

\SEEALSO
ABS_TAC, AP_TERM_TAC, AP_THM, BINOP_TAC, MK_COMB_TAC.

\ENDDOC