ALLGOALS : tactic -> list_tactic
Applies a tactic to every goal in a list
If tac is a tactic, ALLGOALS tac is a list-tactic which
applies the tactic tac to all the goals in the given list.
The application of ALLGOALS to a tactic never fails.
The resulting list-tactic fails if
tac fails when applied to any of the goals in the given list.
Where tac1 and tac2 are tactics,
tac1 THEN_LT ALLGOALS tac2 is equivalent to tac1 THEN tac2