goalstackLib.set_backup : int -> unit
#set_backup 0; () unit #g "(HD[1;2;3] = 1) /\ (TL[1;2;3] = [2;3])";; "(HD[1;2;3] = 1) /\ (TL[1;2;3] = [2;3])" () : void #e CONJ_TAC;; OK.. 2 subgoals "TL[1;2;3] = [2;3]" "HD[1;2;3] = 1" () : void #e (REWRITE_TAC[HD]);; OK.. goal proved |- HD[1;2;3] = 1 Previous subproof: "TL[1;2;3] = [2;3]" () : void #b();; 2 subgoals "TL[1;2;3] = [2;3]" "HD[1;2;3] = 1" () : void #b();; evaluation failed backup: backup list is empty