PURE_CASE_TACBasicProvers.PURE_CASE_TAC : tactic
Case splits on a term t that features in the goal as
case t of ....
BasicProvers.PURE_CASE_TAC searches the goal for an
instance of case t of ..., and performs a
BasicProvers.Cases_on `t`.
BasicProvers.PURE_CASE_TAC fails if there is no instance
of case t of ... in the goal, where the case
term is a case constant in the typebase and all the free variables of
t are free in the goal.