PSELECT_INTRO
PairRules.PSELECT_INTRO : (thm -> thm)
Introduces an epsilon term.
PSELECT_INTRO
takes a theorem with an applicative
conclusion, say P x
, and returns a theorem with the epsilon
term $@ P
in place of the original operand
x
.
A |- P x
-------------- PSELECT_INTRO
A |- P($@ P)
The returned theorem asserts that $@ P
denotes some
value at which P
holds.
Fails if the conclusion of the theorem is not an application.
This function is exactly the same as SELECT_INTRO
, it is
duplicated in the pair library for completeness.
Drule.SELECT_INTRO
, PairRules.PEXISTS
, PairRules.PSELECT_CONV
,
PairRules.PSELECT_ELIM
,
PairRules.PSELECT_RULE