ASSUM_LIST : (thm list -> tactic) -> tactic
ASSUM_LIST f ({A1,...,An} ?- t) = f [A1 |- A1, ... , An |- An] ({A1,...,An} ?- t)
ASSUM_LIST SUBST_TACmakes a single parallel substitution using all the assumptions, which can be useful if the rewriting tactics are too blunt for the required task.