HEADGOAL
Tactical.HEADGOAL : tactic -> list_tactic
The list-tactic which applies a tactic to the first member of a list of goals.
If tac
is a tactic, HEADGOAL tac
is a
list-tactic which applies the tactic tac
to the first
member of a list of goals.
The application of HEADGOAL
to a tactic never fails. The
resulting list-tactic fails the goal list is empty or or finally if
tac
fails when applied to the first member of the goal
list.
Applying a tactic to the first subgoal.
Where tac1
and tac2
are tactics,
tac1 THEN_LT HEADGOAL tac2
applies tac1
to a
goal, and then applies tac2
to the first resulting
subgoal.
Tactical.THEN_LT
, Tactical.NTH_GOAL
, Tactical.THEN1
, Tactical.LASTGOAL