apply (refl_sym_is_sym_refl _ _ _).1
case a.a
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x✝¹ y✝¹ : A
a✝¹ : refl_clos (trans_clos (sym_clos R)) x✝¹ y✝¹
x✝ y✝ : A
a✝ : ?a.R✝ x✝ y✝
⊢ sym_clos (refl_clos R) x✝ y✝
case a.a
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x✝¹ y✝¹ : A
a✝¹ : refl_clos (trans_clos (sym_clos R)) x✝¹ y✝¹
x✝ y✝ : A
a✝ : ?a.R✝ x✝ y✝
⊢ refl_clos (sym_clos R) x✝ y✝