Theorem xpord2indlem 8201

Description: Induction over the Cartesian product ordering. Note that the substitutions cover all possible cases of membership in the predecessor class. (Contributed by Scott Fenton, 22-Aug-2024.)

Hypotheses

Ref	Expression
xpord2.1	⊢ 𝑇 = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴 × 𝐵) ∧ 𝑦 ∈ (𝐴 × 𝐵) ∧ (((1st ‘𝑥)𝑅(1st ‘𝑦) ∨ (1st ‘𝑥) = (1st ‘𝑦)) ∧ ((2nd ‘𝑥)𝑆(2nd ‘𝑦) ∨ (2nd ‘𝑥) = (2nd ‘𝑦)) ∧ 𝑥 ≠ 𝑦))}
xpord2indlem.1	⊢ 𝑅 Fr 𝐴
xpord2indlem.2	⊢ 𝑅 Po 𝐴
xpord2indlem.3	⊢ 𝑅 Se 𝐴
xpord2indlem.4	⊢ 𝑆 Fr 𝐵
xpord2indlem.5	⊢ 𝑆 Po 𝐵
xpord2indlem.6	⊢ 𝑆 Se 𝐵
xpord2indlem.7	⊢ (𝑎 = 𝑐 → (𝜑 ↔ 𝜓))
xpord2indlem.8	⊢ (𝑏 = 𝑑 → (𝜓 ↔ 𝜒))
xpord2indlem.9	⊢ (𝑎 = 𝑐 → (𝜃 ↔ 𝜒))
xpord2indlem.11	⊢ (𝑎 = 𝑋 → (𝜑 ↔ 𝜏))
xpord2indlem.12	⊢ (𝑏 = 𝑌 → (𝜏 ↔ 𝜂))
xpord2indlem.i	⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → ((∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒 ∧ ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)𝜓 ∧ ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜃) → 𝜑))

Assertion

Ref	Expression
xpord2indlem	⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → 𝜂)

Distinct variable groups:   𝐴,𝑎,𝑏,𝑐,𝑑   𝜓,𝑎   𝜏,𝑎   𝑥,𝐴,𝑦   𝐵,𝑎,𝑏,𝑐,𝑑   𝜒,𝑏   𝜂,𝑏   𝑥,𝐵,𝑦   𝜑,𝑐   𝜃,𝑐   𝜓,𝑑   𝑅,𝑐,𝑑   𝑥,𝑅,𝑦   𝑆,𝑐,𝑑   𝑥,𝑆,𝑦   𝑇,𝑎,𝑏,𝑐,𝑑   𝑋,𝑎,𝑏   𝑌,𝑏

Allowed substitution hints:   𝜑(𝑥, 𝑦, 𝑎, 𝑏, 𝑑)   𝜓(𝑥, 𝑦, 𝑏, 𝑐)   𝜒(𝑥, 𝑦, 𝑎, 𝑐, 𝑑)   𝜃(𝑥, 𝑦, 𝑎, 𝑏, 𝑑)   𝜏(𝑥, 𝑦, 𝑏, 𝑐, 𝑑)   𝜂(𝑥, 𝑦, 𝑎, 𝑐, 𝑑)   𝑅(𝑎, 𝑏)   𝑆(𝑎, 𝑏)   𝑇(𝑥, 𝑦)   𝑋(𝑥, 𝑦, 𝑐, 𝑑)   𝑌(𝑥, 𝑦, 𝑎, 𝑐, 𝑑)

Proof of Theorem xpord2indlem

Step	Hyp	Ref	Expression
1		xpord2.1	. . . . 5 ⊢ 𝑇 = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴 × 𝐵) ∧ 𝑦 ∈ (𝐴 × 𝐵) ∧ (((1st ‘𝑥)𝑅(1st ‘𝑦) ∨ (1st ‘𝑥) = (1st ‘𝑦)) ∧ ((2nd ‘𝑥)𝑆(2nd ‘𝑦) ∨ (2nd ‘𝑥) = (2nd ‘𝑦)) ∧ 𝑥 ≠ 𝑦))}
2		xpord2indlem.1	. . . . . 6 ⊢ 𝑅 Fr 𝐴
3	2	a1i 11	. . . . 5 ⊢ (⊤ → 𝑅 Fr 𝐴)
4		xpord2indlem.4	. . . . . 6 ⊢ 𝑆 Fr 𝐵
5	4	a1i 11	. . . . 5 ⊢ (⊤ → 𝑆 Fr 𝐵)
6	1, 3, 5	frxp2 8198	. . . 4 ⊢ (⊤ → 𝑇 Fr (𝐴 × 𝐵))
7		xpord2indlem.2	. . . . . 6 ⊢ 𝑅 Po 𝐴
8	7	a1i 11	. . . . 5 ⊢ (⊤ → 𝑅 Po 𝐴)
9		xpord2indlem.5	. . . . . 6 ⊢ 𝑆 Po 𝐵
10	9	a1i 11	. . . . 5 ⊢ (⊤ → 𝑆 Po 𝐵)
11	1, 8, 10	poxp2 8197	. . . 4 ⊢ (⊤ → 𝑇 Po (𝐴 × 𝐵))
12		xpord2indlem.3	. . . . . 6 ⊢ 𝑅 Se 𝐴
13	12	a1i 11	. . . . 5 ⊢ (⊤ → 𝑅 Se 𝐴)
14		xpord2indlem.6	. . . . . 6 ⊢ 𝑆 Se 𝐵
15	14	a1i 11	. . . . 5 ⊢ (⊤ → 𝑆 Se 𝐵)
16	1, 13, 15	sexp2 8200	. . . 4 ⊢ (⊤ → 𝑇 Se (𝐴 × 𝐵))
17	6, 11, 16	3jca 1146	. . 3 ⊢ (⊤ → (𝑇 Fr (𝐴 × 𝐵) ∧ 𝑇 Po (𝐴 × 𝐵) ∧ 𝑇 Se (𝐴 × 𝐵)))
18	17	mptru 1577	. 2 ⊢ (𝑇 Fr (𝐴 × 𝐵) ∧ 𝑇 Po (𝐴 × 𝐵) ∧ 𝑇 Se (𝐴 × 𝐵))
19	1	xpord2pred 8199	. . . . . . . . 9 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) = (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}))
20	19	eleq2d 2850	. . . . . . . 8 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) ↔ ⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩})))
21	20	imbi1d 344	. . . . . . 7 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → ((⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) → 𝜒) ↔ (⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}) → 𝜒)))
22		eldif 4052	. . . . . . . . . 10 ⊢ (⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}) ↔ (⟨𝑐, 𝑑⟩ ∈ ((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ ¬ ⟨𝑐, 𝑑⟩ ∈ {⟨𝑎, 𝑏⟩}))
23		opelxp 5694	. . . . . . . . . . 11 ⊢ (⟨𝑐, 𝑑⟩ ∈ ((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ↔ (𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})))
24		opex 5439	. . . . . . . . . . . . . 14 ⊢ ⟨𝑐, 𝑑⟩ ∈ V
25	24	elsn 4599	. . . . . . . . . . . . 13 ⊢ (⟨𝑐, 𝑑⟩ ∈ {⟨𝑎, 𝑏⟩} ↔ ⟨𝑐, 𝑑⟩ = ⟨𝑎, 𝑏⟩)
26	25	notbii 323	. . . . . . . . . . . 12 ⊢ (¬ ⟨𝑐, 𝑑⟩ ∈ {⟨𝑎, 𝑏⟩} ↔ ¬ ⟨𝑐, 𝑑⟩ = ⟨𝑎, 𝑏⟩)
27		df-ne 2960	. . . . . . . . . . . 12 ⊢ (⟨𝑐, 𝑑⟩ ≠ ⟨𝑎, 𝑏⟩ ↔ ¬ ⟨𝑐, 𝑑⟩ = ⟨𝑎, 𝑏⟩)
28		vex 3458	. . . . . . . . . . . . 13 ⊢ 𝑐 ∈ V
29		vex 3458	. . . . . . . . . . . . 13 ⊢ 𝑑 ∈ V
30	28, 29	opthne 5458	. . . . . . . . . . . 12 ⊢ (⟨𝑐, 𝑑⟩ ≠ ⟨𝑎, 𝑏⟩ ↔ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏))
31	26, 27, 30	3bitr2i 302	. . . . . . . . . . 11 ⊢ (¬ ⟨𝑐, 𝑑⟩ ∈ {⟨𝑎, 𝑏⟩} ↔ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏))
32	23, 31	anbi12i 640	. . . . . . . . . 10 ⊢ ((⟨𝑐, 𝑑⟩ ∈ ((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ ¬ ⟨𝑐, 𝑑⟩ ∈ {⟨𝑎, 𝑏⟩}) ↔ ((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏)))
33	22, 32	bitri 278	. . . . . . . . 9 ⊢ (⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}) ↔ ((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏)))
34	33	imbi1i 352	. . . . . . . 8 ⊢ ((⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}) → 𝜒) ↔ (((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏)) → 𝜒))
35		impexp 456	. . . . . . . 8 ⊢ ((((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∧ (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏)) → 𝜒) ↔ ((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
36	34, 35	bitri 278	. . . . . . 7 ⊢ ((⟨𝑐, 𝑑⟩ ∈ (((Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) × (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) ∖ {⟨𝑎, 𝑏⟩}) → 𝜒) ↔ ((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
37	21, 36	bitrdi 290	. . . . . 6 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → ((⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) → 𝜒) ↔ ((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))))
38	37	2albidv 1958	. . . . 5 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (∀𝑐∀𝑑(⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) → 𝜒) ↔ ∀𝑐∀𝑑((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))))
39		r2al 3202	. . . . 5 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ∀𝑐∀𝑑((𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) ∧ 𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})) → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
40	38, 39	bitr4di 292	. . . 4 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (∀𝑐∀𝑑(⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) → 𝜒) ↔ ∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
41		ssun1 4179	. . . . . . . . 9 ⊢ Pred(𝑅, 𝐴, 𝑎) ⊆ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})
42		ssralv 3982	. . . . . . . . 9 ⊢ (Pred(𝑅, 𝐴, 𝑎) ⊆ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) → (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
43	41, 42	ax-mp 5	. . . . . . . 8 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
44		ssun1 4179	. . . . . . . . . 10 ⊢ Pred(𝑆, 𝐵, 𝑏) ⊆ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})
45		ssralv 3982	. . . . . . . . . 10 ⊢ (Pred(𝑆, 𝐵, 𝑏) ⊆ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏}) → (∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
46	44, 45	ax-mp 5	. . . . . . . . 9 ⊢ (∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
47	46	ralimi 3103	. . . . . . . 8 ⊢ (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
48	43, 47	syl 18	. . . . . . 7 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
49		predpoirr 6362	. . . . . . . . . . . . . 14 ⊢ (𝑆 Po 𝐵 → ¬ 𝑏 ∈ Pred(𝑆, 𝐵, 𝑏))
50	9, 49	ax-mp 5	. . . . . . . . . . . . 13 ⊢ ¬ 𝑏 ∈ Pred(𝑆, 𝐵, 𝑏)
51		eleq1w 2847	. . . . . . . . . . . . 13 ⊢ (𝑑 = 𝑏 → (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) ↔ 𝑏 ∈ Pred(𝑆, 𝐵, 𝑏)))
52	50, 51	mtbiri 330	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑏 → ¬ 𝑑 ∈ Pred(𝑆, 𝐵, 𝑏))
53	52	necon2ai 2988	. . . . . . . . . . 11 ⊢ (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) → 𝑑 ≠ 𝑏)
54	53	olcd 888	. . . . . . . . . 10 ⊢ (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) → (𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏))
55		pm2.27 43	. . . . . . . . . 10 ⊢ ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → (((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → 𝜒))
56	54, 55	syl 18	. . . . . . . . 9 ⊢ (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) → (((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → 𝜒))
57	56	ralimia 3100	. . . . . . . 8 ⊢ (∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒)
58	57	ralimi 3103	. . . . . . 7 ⊢ (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒)
59	48, 58	syl 18	. . . . . 6 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒)
60		ssun2 4180	. . . . . . . . . . 11 ⊢ {𝑏} ⊆ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})
61		ssralv 3982	. . . . . . . . . . 11 ⊢ ({𝑏} ⊆ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏}) → (∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
62	60, 61	ax-mp 5	. . . . . . . . . 10 ⊢ (∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
63	62	ralimi 3103	. . . . . . . . 9 ⊢ (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
64	43, 63	syl 18	. . . . . . . 8 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
65		vex 3458	. . . . . . . . . 10 ⊢ 𝑏 ∈ V
66		neeq1 3021	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑏 → (𝑑 ≠ 𝑏 ↔ 𝑏 ≠ 𝑏))
67	66	orbi2d 929	. . . . . . . . . . 11 ⊢ (𝑑 = 𝑏 → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) ↔ (𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏)))
68		xpord2indlem.8	. . . . . . . . . . . . 13 ⊢ (𝑏 = 𝑑 → (𝜓 ↔ 𝜒))
69	68	equcoms 2055	. . . . . . . . . . . 12 ⊢ (𝑑 = 𝑏 → (𝜓 ↔ 𝜒))
70	69	bicomd 226	. . . . . . . . . . 11 ⊢ (𝑑 = 𝑏 → (𝜒 ↔ 𝜓))
71	67, 70	imbi12d 347	. . . . . . . . . 10 ⊢ (𝑑 = 𝑏 → (((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓)))
72	65, 71	ralsn 4643	. . . . . . . . 9 ⊢ (∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓))
73	72	ralbii 3112	. . . . . . . 8 ⊢ (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ {𝑏} ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓))
74	64, 73	sylib 221	. . . . . . 7 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓))
75		predpoirr 6362	. . . . . . . . . . . . 13 ⊢ (𝑅 Po 𝐴 → ¬ 𝑎 ∈ Pred(𝑅, 𝐴, 𝑎))
76	7, 75	ax-mp 5	. . . . . . . . . . . 12 ⊢ ¬ 𝑎 ∈ Pred(𝑅, 𝐴, 𝑎)
77		eleq1w 2847	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑎 → (𝑐 ∈ Pred(𝑅, 𝐴, 𝑎) ↔ 𝑎 ∈ Pred(𝑅, 𝐴, 𝑎)))
78	76, 77	mtbiri 330	. . . . . . . . . . 11 ⊢ (𝑐 = 𝑎 → ¬ 𝑐 ∈ Pred(𝑅, 𝐴, 𝑎))
79	78	necon2ai 2988	. . . . . . . . . 10 ⊢ (𝑐 ∈ Pred(𝑅, 𝐴, 𝑎) → 𝑐 ≠ 𝑎)
80	79	orcd 887	. . . . . . . . 9 ⊢ (𝑐 ∈ Pred(𝑅, 𝐴, 𝑎) → (𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏))
81		pm2.27 43	. . . . . . . . 9 ⊢ ((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → (((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓) → 𝜓))
82	80, 81	syl 18	. . . . . . . 8 ⊢ (𝑐 ∈ Pred(𝑅, 𝐴, 𝑎) → (((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓) → 𝜓))
83	82	ralimia 3100	. . . . . . 7 ⊢ (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)((𝑐 ≠ 𝑎 ∨ 𝑏 ≠ 𝑏) → 𝜓) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)𝜓)
84	74, 83	syl 18	. . . . . 6 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)𝜓)
85		ssun2 4180	. . . . . . . . . 10 ⊢ {𝑎} ⊆ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})
86		ssralv 3982	. . . . . . . . . 10 ⊢ ({𝑎} ⊆ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎}) → (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ {𝑎}∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒)))
87	85, 86	ax-mp 5	. . . . . . . . 9 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ {𝑎}∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
88	46	ralimi 3103	. . . . . . . . 9 ⊢ (∀𝑐 ∈ {𝑎}∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ {𝑎}∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
89	87, 88	syl 18	. . . . . . . 8 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑐 ∈ {𝑎}∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒))
90		vex 3458	. . . . . . . . 9 ⊢ 𝑎 ∈ V
91		neeq1 3021	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑎 → (𝑐 ≠ 𝑎 ↔ 𝑎 ≠ 𝑎))
92	91	orbi1d 930	. . . . . . . . . . 11 ⊢ (𝑐 = 𝑎 → ((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) ↔ (𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏)))
93		xpord2indlem.9	. . . . . . . . . . . . 13 ⊢ (𝑎 = 𝑐 → (𝜃 ↔ 𝜒))
94	93	equcoms 2055	. . . . . . . . . . . 12 ⊢ (𝑐 = 𝑎 → (𝜃 ↔ 𝜒))
95	94	bicomd 226	. . . . . . . . . . 11 ⊢ (𝑐 = 𝑎 → (𝜒 ↔ 𝜃))
96	92, 95	imbi12d 347	. . . . . . . . . 10 ⊢ (𝑐 = 𝑎 → (((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃)))
97	96	ralbidv 3189	. . . . . . . . 9 ⊢ (𝑐 = 𝑎 → (∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃)))
98	90, 97	ralsn 4643	. . . . . . . 8 ⊢ (∀𝑐 ∈ {𝑎}∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) ↔ ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃))
99	89, 98	sylib 221	. . . . . . 7 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃))
100	53	olcd 888	. . . . . . . . 9 ⊢ (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) → (𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏))
101		pm2.27 43	. . . . . . . . 9 ⊢ ((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → (((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃) → 𝜃))
102	100, 101	syl 18	. . . . . . . 8 ⊢ (𝑑 ∈ Pred(𝑆, 𝐵, 𝑏) → (((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃) → 𝜃))
103	102	ralimia 3100	. . . . . . 7 ⊢ (∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)((𝑎 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜃) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜃)
104	99, 103	syl 18	. . . . . 6 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜃)
105	59, 84, 104	3jca 1146	. . . . 5 ⊢ (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → (∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒 ∧ ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)𝜓 ∧ ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜃))
106		xpord2indlem.i	. . . . 5 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → ((∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜒 ∧ ∀𝑐 ∈ Pred (𝑅, 𝐴, 𝑎)𝜓 ∧ ∀𝑑 ∈ Pred (𝑆, 𝐵, 𝑏)𝜃) → 𝜑))
107	105, 106	syl5 35	. . . 4 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (∀𝑐 ∈ (Pred(𝑅, 𝐴, 𝑎) ∪ {𝑎})∀𝑑 ∈ (Pred(𝑆, 𝐵, 𝑏) ∪ {𝑏})((𝑐 ≠ 𝑎 ∨ 𝑑 ≠ 𝑏) → 𝜒) → 𝜑))
108	40, 107	sylbid 243	. . 3 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (∀𝑐∀𝑑(⟨𝑐, 𝑑⟩ ∈ Pred(𝑇, (𝐴 × 𝐵), ⟨𝑎, 𝑏⟩) → 𝜒) → 𝜑))
109		xpord2indlem.7	. . 3 ⊢ (𝑎 = 𝑐 → (𝜑 ↔ 𝜓))
110		xpord2indlem.11	. . 3 ⊢ (𝑎 = 𝑋 → (𝜑 ↔ 𝜏))
111		xpord2indlem.12	. . 3 ⊢ (𝑏 = 𝑌 → (𝜏 ↔ 𝜂))
112	108, 109, 68, 110, 111	frpoins3xpg 8194	. 2 ⊢ (((𝑇 Fr (𝐴 × 𝐵) ∧ 𝑇 Po (𝐴 × 𝐵) ∧ 𝑇 Se (𝐴 × 𝐵)) ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵)) → 𝜂)
113	18, 112	mpan 703	1 ⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵) → 𝜂)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401   ∨ wo 861   ∧ w3a 1103  ∀wal 1568   = wceq 1570  ⊤wtru 1571   ∈ wcel 2147   ≠ wne 2959  ∀wral 3080   ⊆ wss 3900   ∖ cdif 4048   ∪ cun 4152  {csn 4588  ⟨cop 4840   class class class wbr 5108  {copab 5173   Po wpo 5564   Fr wfr 5608   Se wse 5609   × cxp 5656  Predcpred 6329  ‘cfv 6566  1^st c1st 8033  2^nd c2nd 8034

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-ext 2735  ax-sep 5255  ax-nul 5266  ax-pow 5334  ax-pr 5398  ax-un 7783

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2102  df-mo 2567  df-eu 2597  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-ne 2960  df-ral 3081  df-rex 3091  df-rab 3417  df-v 3456  df-sbc 3743  df-csb 3852  df-ss 3901  df-dif 4050  df-in 4094  df-un 4154  df-nul 4282  df-if 4486  df-pw 4562  df-sn 4589  df-pr 4591  df-op 4841  df-uni 4873  df-iun 4958  df-br 5109  df-opab 5174  df-mpt 5193  df-id 5553  df-po 5566  df-fr 5611  df-se 5612  df-xp 5664  df-rel 5665  df-cnv 5666  df-co 5667  df-dm 5668  df-rn 5669  df-res 5670  df-ima 5671  df-pred 6330  df-iota 6520  df-fun 6568  df-fv 6574  df-1st 8035  df-2nd 8036

This theorem is used by:  xpord2ind  8202