b : (void -> void)

SYNOPSIS
Restores the proof state undoing the effects of a previous expansion.

DESCRIBE
The function b is part of the subgoal package. It is an abbreviation for the function backup. For a description of the subgoal package, see set_goal.

FAILURE
As for backup.

USES
Back tracking in a goal-directed proof to undo errors or try different tactics.

SEEALSO  backup,   backup_limit,   e,   expand,   expandf,   g,   get_state,   p,   print_state,   r,   rotate,   save_top_thm,   set_goal,   set_state,   top_goal,   top_thm

HOL  Kananaskis 0