Goal:
    A : Type  j : positive  m1 : tree' A  m2 : tree' A  H : xH <> xO j
  ============================
   (None = None)


DEBUG:Going to execute:
<coq-core.plugins.ltac::auto@0> $1 $2 $3

Goals:

DEBUG:Going to execute:
apply IHi

Goals:

DEBUG:Going to execute:
congruence

Goals:

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