Goal:
    x : string  y : string  z : string  H : lt x y  H0 : lt y z
  ============================
   (lt ?x y)


DEBUG:Going to execute:
eassumption
Level 0: Backtrace:

Tactic failure: congruence failed.
Level 0: Backtrace:

Tactic failure: congruence failed.
DEBUG LTAC Evaluated term: transitivity