Goal:
  
  A : Type
  f : A -> bool
  g : A -> bool
  a : A
  Hf : forall x : A, f x -> g x
  H : is_true (foroptb f (Some a))
  ============================
   (true = foroptb g (Some a))


DEBUG:Going to execute:
<coq-core.plugins.ltac::trivial@0> $1 $2