Metamath Proof Explorer


Theorem enqer

Description: The equivalence relation for positive fractions is an equivalence relation. Proposition 9-2.1 of Gleason p. 117. (Contributed by NM, 27-Aug-1995) (Revised by Mario Carneiro, 6-Jul-2015) (New usage is discouraged.)

Ref Expression
Assertion enqer ⊢ ~ 𝑸 Er 𝑵 × 𝑵

Proof

Step Hyp Ref Expression
1 df-enq ⊢ ~ 𝑸 = x y | x ∈ 𝑵 × 𝑵 ∧ y ∈ 𝑵 × 𝑵 ∧ ∃ z ∃ w ∃ v ∃ u x = z w ∧ y = v u ∧ z ⋅ 𝑵 u = w ⋅ 𝑵 v
2 mulcompi ⊢ x ⋅ 𝑵 y = y ⋅ 𝑵 x
3 mulclpi ⊢ x ∈ 𝑵 ∧ y ∈ 𝑵 → x ⋅ 𝑵 y ∈ 𝑵
4 mulasspi ⊢ x ⋅ 𝑵 y ⋅ 𝑵 z = x ⋅ 𝑵 y ⋅ 𝑵 z
5 mulcanpi ⊢ x ∈ 𝑵 ∧ y ∈ 𝑵 → x ⋅ 𝑵 y = x ⋅ 𝑵 z ↔ y = z
6 5 biimpd ⊢ x ∈ 𝑵 ∧ y ∈ 𝑵 → x ⋅ 𝑵 y = x ⋅ 𝑵 z → y = z
7 1 2 3 4 6 ecopover ⊢ ~ 𝑸 Er 𝑵 × 𝑵