+ | [ IDENT "undo" | IDENT "Undo" ]; steps = OPT NUM ->
+ return_command loc (TacticAst.Undo (int_opt steps))
+ | [ IDENT "redo" | IDENT "Redo" ]; steps = OPT NUM ->
+ return_command loc (TacticAst.Redo (int_opt steps))
+ | [ IDENT "check" | IDENT "Check" ]; t = term ->
+ return_command loc (TacticAst.Check t)