Goal:
    m : t  n : t  H : n = m
  ============================
   (n = m \/ False)


DEBUG:Going to execute:
solve [ Ltac.left; t_tauto_intuit | Ltac.right; t_tauto_intuit ]
Level 2: evaluation returns
<coq-core.plugins.tauto::is_disj@0>
where
tauto_flags := 
of type
tauto_flags
X1 := n = m \/ False
of type
constr of type tacvalue