Module Segfault.
Inductive decision_tree : Type := .
Fixpoint first_satisfying_helper {A B} (f : A -> option B) (ls : list A) : option B
:= match ls with
| nil => None
| cons x xs
=> match f x with
| Some v => Some v
| None => first_satisfying_helper f xs
end
end.

Axiom admit : forall {T}, T.