TRY_LT : (list_tactic -> list_tactic)
STRUCTURE
SYNOPSIS
Makes a list-tactic have no effect rather than fail.
DESCRIPTION
For any list-tactic ltac, the application TRY_LT ltac gives a new list-tactic which has the same effect as ltac if that succeeds, and otherwise has no effect.
FAILURE
The application of TRY_LT to a list-tactic never fails. The resulting list-tactic never fails.
SEEALSO
HOL  Kananaskis-13