Goal:
    A : Type  R : relation A  S : relation A  HR : Reflexive R  x : A
  ============================
   (relation_disjunction R S x x)


DEBUG:Going to execute:
left
DEBUG LTAC Evaluated term: relation_equivalence_inclusion
DEBUG LTAC Evaluated term: clos_t_rt_incl
DEBUG LTAC Evaluated term: clos_rt_t_incl