Definition df-ltpq 7147

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

Assertion

Ref	Expression
df-ltpq	⊢ <pQ = {⟨𝑥, 𝑦⟩ ∣ ((𝑥 ∈ (N × N) ∧ 𝑦 ∈ (N × N)) ∧ ((1st ‘𝑥) ·N (2nd ‘𝑦)) <N ((1st ‘𝑦) ·N (2nd ‘𝑥)))}

Distinct variable group:   𝑥,𝑦

Detailed syntax breakdown of Definition df-ltpq

Step	Hyp	Ref	Expression
1		cltpq 7079	. 2 class <pQ
2		vx	. . . . . . 7 setvar 𝑥
3	2	cv 1330	. . . . . 6 class 𝑥
4		cnpi 7073	. . . . . . 7 class N
5	4, 4	cxp 4532	. . . . . 6 class (N × N)
6	3, 5	wcel 1480	. . . . 5 wff 𝑥 ∈ (N × N)
7		vy	. . . . . . 7 setvar 𝑦
8	7	cv 1330	. . . . . 6 class 𝑦
9	8, 5	wcel 1480	. . . . 5 wff 𝑦 ∈ (N × N)
10	6, 9	wa 103	. . . 4 wff (𝑥 ∈ (N × N) ∧ 𝑦 ∈ (N × N))
11		c1st 6029	. . . . . . 7 class 1st
12	3, 11	cfv 5118	. . . . . 6 class (1st ‘𝑥)
13		c2nd 6030	. . . . . . 7 class 2nd
14	8, 13	cfv 5118	. . . . . 6 class (2nd ‘𝑦)
15		cmi 7075	. . . . . 6 class ·N
16	12, 14, 15	co 5767	. . . . 5 class ((1st ‘𝑥) ·N (2nd ‘𝑦))
17	8, 11	cfv 5118	. . . . . 6 class (1st ‘𝑦)
18	3, 13	cfv 5118	. . . . . 6 class (2nd ‘𝑥)
19	17, 18, 15	co 5767	. . . . 5 class ((1st ‘𝑦) ·N (2nd ‘𝑥))
20		clti 7076	. . . . 5 class <N
21	16, 19, 20	wbr 3924	. . . 4 wff ((1st ‘𝑥) ·N (2nd ‘𝑦)) <N ((1st ‘𝑦) ·N (2nd ‘𝑥))
22	10, 21	wa 103	. . 3 wff ((𝑥 ∈ (N × N) ∧ 𝑦 ∈ (N × N)) ∧ ((1st ‘𝑥) ·N (2nd ‘𝑦)) <N ((1st ‘𝑦) ·N (2nd ‘𝑥)))
23	22, 2, 7	copab 3983	. 2 class {⟨𝑥, 𝑦⟩ ∣ ((𝑥 ∈ (N × N) ∧ 𝑦 ∈ (N × N)) ∧ ((1st ‘𝑥) ·N (2nd ‘𝑦)) <N ((1st ‘𝑦) ·N (2nd ‘𝑥)))}
24	1, 23	wceq 1331	1 wff <pQ = {⟨𝑥, 𝑦⟩ ∣ ((𝑥 ∈ (N × N) ∧ 𝑦 ∈ (N × N)) ∧ ((1st ‘𝑥) ·N (2nd ‘𝑦)) <N ((1st ‘𝑦) ·N (2nd ‘𝑥)))}

This definition is referenced by: (None)