Goal:
  
  G : t
  HI : invariants
  A : Prop
  B : Prop
  b : B
  H0 : A -> B
  H1 : B -> A
  ============================
   A


DEBUG:Going to execute:
F x2 x1 x0
Level 2: evaluation returns
<coq-core.plugins.tauto::find_cut@0>
where
k := fun id0 id1 X2 => assert X2; [ exact (id0 id1) | clear id0 ]
     where
     flags := 
     of type
     tauto_flags
of type
tacvalue of type tacvalue