Goal:
    A : Type  P : A → Type  Q : A → Type
  ============================
   (All P [] × All Q [])


DEBUG:Going to execute:
Ltac.split
Level 2: evaluation returns
<coq-core.plugins.tauto::is_conj@0>
where
tauto_flags := 
of type
tauto_flags
X1 := All P [] × All Q []
of type
constr of type tacvalue