Metamath Proof Explorer


Theorem relsdom

Description: Strict dominance is a relation. (Contributed by NM, 31-Mar-1998)

Ref Expression
Assertion relsdom ⊢ Rel ⁡ ≺

Proof

Step Hyp Ref Expression
1 reldom ⊢ Rel ⁡ ≼
2 reldif ⊢ Rel ⁡ ≼ → Rel ⁡ ≼ ∖ ≈
3 df-sdom ⊢ ≺ = ≼ ∖ ≈
4 3 releqi ⊢ Rel ⁡ ≺ ↔ Rel ⁡ ≼ ∖ ≈
5 2 4 sylibr ⊢ Rel ⁡ ≼ → Rel ⁡ ≺
6 1 5 ax-mp ⊢ Rel ⁡ ≺