Metamath Proof Explorer


Definition df-ltpq

Description: Define pre-ordering relation on positive fractions. This is a "temporary" set used in the construction of complex numbers df-c , and is intended to be used only by the construction. Similar to Definition 5 of Suppes p. 162. (Contributed by NM, 28-Aug-1995) (New usage is discouraged.)

Ref Expression
Assertion df-ltpq < 𝑝𝑸 = x y | x 𝑵 × 𝑵 y 𝑵 × 𝑵 1 st x 𝑵 2 nd y < 𝑵 1 st y 𝑵 2 nd x

Detailed syntax breakdown

Step Hyp Ref Expression
0 cltpq class < 𝑝𝑸
1 vx setvar x
2 vy setvar y
3 1 cv setvar x
4 cnpi class 𝑵
5 4 4 cxp class 𝑵 × 𝑵
6 3 5 wcel wff x 𝑵 × 𝑵
7 2 cv setvar y
8 7 5 wcel wff y 𝑵 × 𝑵
9 6 8 wa wff x 𝑵 × 𝑵 y 𝑵 × 𝑵
10 c1st class 1 st
11 3 10 cfv class 1 st x
12 cmi class 𝑵
13 c2nd class 2 nd
14 7 13 cfv class 2 nd y
15 11 14 12 co class 1 st x 𝑵 2 nd y
16 clti class < 𝑵
17 7 10 cfv class 1 st y
18 3 13 cfv class 2 nd x
19 17 18 12 co class 1 st y 𝑵 2 nd x
20 15 19 16 wbr wff 1 st x 𝑵 2 nd y < 𝑵 1 st y 𝑵 2 nd x
21 9 20 wa wff x 𝑵 × 𝑵 y 𝑵 × 𝑵 1 st x 𝑵 2 nd y < 𝑵 1 st y 𝑵 2 nd x
22 21 1 2 copab class x y | x 𝑵 × 𝑵 y 𝑵 × 𝑵 1 st x 𝑵 2 nd y < 𝑵 1 st y 𝑵 2 nd x
23 0 22 wceq wff < 𝑝𝑸 = x y | x 𝑵 × 𝑵 y 𝑵 × 𝑵 1 st x 𝑵 2 nd y < 𝑵 1 st y 𝑵 2 nd x