MK_PEXISTSPairRules.MK_PEXISTS : (thm -> thm)
Existentially quantifies both sides of a universally quantified equational theorem.
When applied to a theorem A |- !p. t1 = t2, the
inference rule MK_PEXISTS returns the theorem
A |- (?x. t1) = (?x. t2).
A |- !p. t1 = t2
-------------------------- MK_PEXISTS
A |- (?p. t1) = (?p. t2)
Fails unless the theorem is a singly paired universally quantified equation.
PairRules.PEXISTS_EQ,
PairRules.PGEN, PairRules.LIST_MK_PEXISTS,
PairRules.MK_PABS