Goal:
  
  A : Type
  R : ReflectEq A
  x : A
  y : A
  Heq_anonymous : false = (x == y)
  H : x = y
  ============================
   False


DEBUG:Going to execute:
fun H =>
             let ph := fresh "X" in
             let ph' := fresh "X" in
             destruct H as [H ph ph']