trivial
case inl.inr.left.a.h
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x y z : X
h✝¹ : y = X.b
h✝ : z = X.d
⊢ ?inl.inr.left.b = X.c

case inl.inr.left.a
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x y z : X
h✝¹ : y = X.b
h✝ : z = X.d
⊢ refl_trans_clos (fun x y => x = X.b ∧ y = X.a ∨ x = X.b ∧ y = X.c ∨ x = X.c ∧ y = X.b ∨ x = X.c ∧ y = X.d)
    ?inl.inr.left.b X.d

case inl.inr.left.b
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x y z : X
h✝¹ : y = X.b
h✝ : z = X.d
⊢ X
case inl.inr.left.a
A : Type
R : A → A → Prop
inhabited_A : Nonempty A
x y z : X
h✝¹ : y = X.b
h✝ : z = X.d
⊢ refl_trans_clos (fun x y => x = X.b ∧ y = X.a ∨ x = X.b ∧ y = X.c ∨ x = X.c ∧ y = X.b ∨ x = X.c ∧ y = X.d) X.c X.d