Theorem po_refl

Theorem. po_refl
partial_order R M → x ∈ M → R x x
Proof
01. 1 ⊢ partial_order R M, hypo.
02. 1 ⊢ ∀x. x ∈ M → R x x, lsubj_conj_elimll po_equi 1.
03. 1 ⊢ x ∈ M → R x x, uq_elim 2.
po_refl. ⊢ partial_order R M → x ∈ M → R x x, subj_intro 3.