ALL_TAC : tactic

SYNOPSIS
Passes on a goal unchanged.

DESCRIBE
ALL_TAC applied to a goal g simply produces the subgoal list [g]. It is the identity for the THEN tactical.

FAILURE
Never fails.

EXAMPLE
The tactic
   INDUCT_THEN numTheory.INDUCTION THENL [ALL_TAC, tac]
applied to a goal g, applies INDUCT_THEN numTheory.INDUCTION to g to give a basis and step subgoal; it then returns the basis unchanged, along with the subgoals produced by applying tac to the step.

USES
Used to write tacticals such as REPEAT. Also, it is often used as a place-holder in building compound tactics using tacticals such as THENL.

SEEALSO  INDUCT_THEN,   NO_TAC,   REPEAT,   THENL

HOL  Kananaskis 0