Goal:
  
  A : Type
  P : A → Prop
  p : A → bool
  q : A → bool
  H : ∀ x : A, P x → p x = q x
  ============================
   (true = true)


DEBUG:Going to execute:
constructor 1
Level 3: evaluation returns
<coq-core.plugins.tauto::is_unit_or_eq@0>
where
tauto_flags := 
of type
tauto_flags
X1 := true = true
of type
constr of type tacvalue