LIST_MK_EXISTSDrule.LIST_MK_EXISTS : (term list -> thm -> thm)
Multiply existentially quantifies both sides of an equation using the given variables.
When applied to a list of terms [x1;...;xn], where the
xi are all variables, and a theorem
A |- t1 = t2, the inference rule
LIST_MK_EXISTS existentially quantifies both sides of the
equation using the variables given, none of which should be free in the
assumption list.
A |- t1 = t2
-------------------------------------- LIST_MK_EXISTS ["x1";...;"xn"]
A |- (?x1...xn. t1) = (?x1...xn. t2)
Fails if any term in the list is not a variable or is free in the assumption list, or if the theorem is not equational.