FIRST_LT

Tactical.FIRST_LT : tactic -> list_tactic

Applies a tactic to the first goal in the goal-list that works.

Given a list of goals gl, an application of FIRST_LT tac to gl will try to apply tac to each goal in gl in turn. If no goal lets tac succeed, the whole application fails also. Otherwise, the first goal on which tac succeeds will generate a (possibly empty) list of new sub-goals. These new sub-goals are pushed onto the front of the rest of gl.

Failure

The application of FIRST_LT to a tactic never fails. The resulting list-tactic fails if the goal list is empty, or if argument tac fails on each goal in the list gl.

Example

> FIRST_LT CONJ_TAC [([], “p ⇒ q”), ([“a ∨ b”], “p /\ q”)]
val it = ([([“a ∨ b”], “p”), ([“a ∨ b”], “q”), ([], “p ⇒ q”)], fn):
  goal list * list_validation

See also

Tactical.THEN_LT, Tactical.HEADGOAL