proofManagerLib.set_backup : int -> unit
- set_backup 0; () unit - g `(HD[1;2;3] = 1) /\ (TL[1;2;3] = [2;3])`; > val it = Proof manager status: 1 proof. 1. Incomplete: Initial goal: (HD [1; 2; 3] = 1) /\ (TL [1; 2; 3] = [2; 3]) : proofs - e CONJ_TAC; OK.. 2 subgoals: > val it = TL [1; 2; 3] = [2; 3] HD [1; 2; 3] = 1 :proof - e (REWRITE_TAC[listTheory.HD]); OK.. Goal proved. |- HD [1; 2; 3] = 1 Remaining subgoals: > val it = TL [1; 2; 3] = [2; 3] : proof - b(); > val it = TL [1; 2; 3] = [2; 3] HD [1; 2; 3] = 1 : proof - b(); ! Uncaught exception: ! CANT_BACKUP_ANYMORE