\DOC PMATCH_MP_TAC
\TYPE {PMATCH_MP_TAC : thm_tactic}
\KEYWORDS
tactic, modus ponens, implication.
\LIBRARY
pair
\SYNOPSIS
Reduces the goal using a supplied implication, with matching.
\DESCRIBE
When applied to a theorem of the form
{
A' |- !p1...pn. s ==> !q1...qm. t
}
{PMATCH_MP_TAC} produces a tactic that reduces a goal whose
conclusion {t'} is a substitution and/or type instance of {t} to the
corresponding instance of {s}. Any variables free in {s} but not in {t}
will
be existentially quantified in the resulting subgoal:
{
A ?- !u1...ui. t'
====================== PMATCH_MP_TAC (A' |- !p1...pn. s ==> !q1...qm.
t)
A ?- ?w1...wp. s'
}
where {w1}, ..., {wp} are (type instances of) those pairs among
{p1}, ..., {pn} having variables that do not occur free in {t}.
Note that this is not a valid tactic unless {A'} is a subset of {A}.
\FAILURE
Fails unless the theorem is an (optionally paired universally quantified)
implication whose consequent can be instantiated to match the goal.
The generalized pairs {u1}, ..., {ui} must occur in {s'} in order for the
conclusion {t} of the supplied theorem to match {t'}.
\SEEALSO
Tactic.MATCH_MP_TAC.
\ENDDOC