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=xy|x𝑵×𝑵y𝑵×𝑵1stx𝑵2ndy<𝑵1sty𝑵2ndx

Detailed syntax breakdown

Step Hyp Ref Expression
0 cltpq class<𝑝𝑸
1 vx setvarx
2 vy setvary
3 1 cv setvarx
4 cnpi class𝑵
5 4 4 cxp class𝑵×𝑵
6 3 5 wcel wffx𝑵×𝑵
7 2 cv setvary
8 7 5 wcel wffy𝑵×𝑵
9 6 8 wa wffx𝑵×𝑵y𝑵×𝑵
10 c1st class1st
11 3 10 cfv class1stx
12 cmi class𝑵
13 c2nd class2nd
14 7 13 cfv class2ndy
15 11 14 12 co class1stx𝑵2ndy
16 clti class<𝑵
17 7 10 cfv class1sty
18 3 13 cfv class2ndx
19 17 18 12 co class1sty𝑵2ndx
20 15 19 16 wbr wff1stx𝑵2ndy<𝑵1sty𝑵2ndx
21 9 20 wa wffx𝑵×𝑵y𝑵×𝑵1stx𝑵2ndy<𝑵1sty𝑵2ndx
22 21 1 2 copab classxy|x𝑵×𝑵y𝑵×𝑵1stx𝑵2ndy<𝑵1sty𝑵2ndx
23 0 22 wceq wff<𝑝𝑸=xy|x𝑵×𝑵y𝑵×𝑵1stx𝑵2ndy<𝑵1sty𝑵2ndx