LAST_ASSUME_TAC
Tactic.LAST_ASSUME_TAC : thm_tactic
Adds an assumption to the top of the assumptions.
Given a theorem th
of the form A' |- u
, and
a goal, LAST_ASSUME_TAC th
adds u
to the
assumptions of the goal.
A ?- t
============== LAST_ASSUME_TAC (A' |- u)
{u} u A ?- t
Note that unless A'
is a subset of A
, this
tactic is invalid.
Never fails.
LAST_ASSUME_TAC
is the naive way of manipulating
assumptions (i.e. without recourse to advanced tacticals); and it is
useful for enriching the assumption list with lemmas as a prelude to
resolution (RES_TAC
, IMP_RES_TAC
), rewriting
with assumptions (ASM_REWRITE_TAC
and so on), and other
operations involving assumptions.