NULL_OK_LT : list_tactic -> list_tactic
STRUCTURE
SYNOPSIS
Makes a list-tactic succeed with no effect when applied to the empty goal list.
DESCRIPTION
For any list-tactic ltac, the application NULL_OK_LT ltac gives a new list-tactic which has the same effect as ltac when applied to a non-empty goal list. Applied to the empty goal list it succeeds with no effect.
FAILURE
The application of NULL_OK_LT to a list-tactic ltac never fails. The resulting list-tactic fails if applied to a non-empty goal list on which ltac fails.
SEEALSO
HOL  Kananaskis-14