EXISTS_DEL_CONVunwindLib.EXISTS_DEL_CONV : conv
Deletes existential quantifiers.
EXISTS_DEL_CONV "?x1 ... xn. t" returns the theorem:
|- (?x1 ... xn. t) = t
provided x1,...,xn are not free in t.
Fails if any of the x’s appear free in t.
The function does not perform a partial deletion; for example, if
x1 and x2 do not appear free in t
but x3 does, the function will fail; it will not
return:
|- ?x1 ... xn. t = ?x3 ... xn. t