X_GEN_TACTactic.X_GEN_TAC : (term -> tactic)
Specializes a goal with the given variable.
When applied to a term x', which should be a variable,
and a goal A ?- !x. t, the tactic X_GEN_TAC
returns the goal A ?- t[x'/x].
A ?- !x. t
============== X_GEN_TAC "x'"
A ?- t[x'/x]
Fails unless the goal’s conclusion is universally quantified and the term a variable of the appropriate type. It also fails if the variable given is free in either the assumptions or (initial) conclusion of the goal.
Tactic.FILTER_GEN_TAC,
Thm.GEN, Thm.GENL, Drule.GEN_ALL, Thm.SPEC, Drule.SPECL, Drule.SPEC_ALL, Tactic.SPEC_TAC, Tactic.STRIP_TAC