Goal:
    x : string  y : string  H : lt y x
  ============================
   (compare y x = Gt -> Gt = Lt)


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

Goals:
    x : string  y : string  H : x = y
  ============================
   (compare y x = Gt -> Eq = Lt)

    x : string  y : string  H : lt x y
  ============================
   (Lt = Lt -> compare y x = Gt)


DEBUG:Going to execute:
subst

Goals:
    x : string  y : string  H : x = y
  ============================
   (compare y x = Gt -> Eq = Lt)

    x : string  y : string  H : lt x y
  ============================
   (Lt = Lt -> compare y x = Gt)


DEBUG:Going to execute:
<coq-core.plugins.ltac::subst@1>