| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | prproropf1o.f | . . . 4
⊢ 𝐹 = (𝑝 ∈ 𝑃 ↦ 〈inf(𝑝, 𝑉, 𝑅), sup(𝑝, 𝑉, 𝑅)〉) | 
| 2 |  | infeq1 9517 | . . . . 5
⊢ (𝑝 = 𝑍 → inf(𝑝, 𝑉, 𝑅) = inf(𝑍, 𝑉, 𝑅)) | 
| 3 |  | supeq1 9486 | . . . . 5
⊢ (𝑝 = 𝑍 → sup(𝑝, 𝑉, 𝑅) = sup(𝑍, 𝑉, 𝑅)) | 
| 4 | 2, 3 | opeq12d 4880 | . . . 4
⊢ (𝑝 = 𝑍 → 〈inf(𝑝, 𝑉, 𝑅), sup(𝑝, 𝑉, 𝑅)〉 = 〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉) | 
| 5 |  | simp3 1138 | . . . 4
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → 𝑍 ∈ 𝑃) | 
| 6 |  | opex 5468 | . . . . 5
⊢
〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 ∈ V | 
| 7 | 6 | a1i 11 | . . . 4
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → 〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 ∈ V) | 
| 8 | 1, 4, 5, 7 | fvmptd3 7038 | . . 3
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → (𝐹‘𝑍) = 〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉) | 
| 9 |  | infeq1 9517 | . . . . 5
⊢ (𝑝 = 𝑊 → inf(𝑝, 𝑉, 𝑅) = inf(𝑊, 𝑉, 𝑅)) | 
| 10 |  | supeq1 9486 | . . . . 5
⊢ (𝑝 = 𝑊 → sup(𝑝, 𝑉, 𝑅) = sup(𝑊, 𝑉, 𝑅)) | 
| 11 | 9, 10 | opeq12d 4880 | . . . 4
⊢ (𝑝 = 𝑊 → 〈inf(𝑝, 𝑉, 𝑅), sup(𝑝, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉) | 
| 12 |  | simp2 1137 | . . . 4
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → 𝑊 ∈ 𝑃) | 
| 13 |  | opex 5468 | . . . . 5
⊢
〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 ∈ V | 
| 14 | 13 | a1i 11 | . . . 4
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 ∈ V) | 
| 15 | 1, 11, 12, 14 | fvmptd3 7038 | . . 3
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → (𝐹‘𝑊) = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉) | 
| 16 | 8, 15 | eqeq12d 2752 | . 2
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → ((𝐹‘𝑍) = (𝐹‘𝑊) ↔ 〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉)) | 
| 17 |  | prproropf1o.p | . . . . 5
⊢ 𝑃 = {𝑝 ∈ 𝒫 𝑉 ∣ (♯‘𝑝) = 2} | 
| 18 | 17 | prpair 47493 | . . . 4
⊢ (𝑍 ∈ 𝑃 ↔ ∃𝑐 ∈ 𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) | 
| 19 | 17 | prpair 47493 | . . . . 5
⊢ (𝑊 ∈ 𝑃 ↔ ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) | 
| 20 |  | id 22 | . . . . . . . . . . . . . . . 16
⊢ (𝑅 Or 𝑉 → 𝑅 Or 𝑉) | 
| 21 | 20 | infexd 9524 | . . . . . . . . . . . . . . 15
⊢ (𝑅 Or 𝑉 → inf({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V) | 
| 22 | 20 | supexd 9494 | . . . . . . . . . . . . . . 15
⊢ (𝑅 Or 𝑉 → sup({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V) | 
| 23 | 21, 22 | jca 511 | . . . . . . . . . . . . . 14
⊢ (𝑅 Or 𝑉 → (inf({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V)) | 
| 24 | 23 | ad4antr 732 | . . . . . . . . . . . . 13
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V)) | 
| 25 |  | opthg 5481 | . . . . . . . . . . . . 13
⊢
((inf({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) ∈ V) → (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)))) | 
| 26 | 24, 25 | syl 17 | . . . . . . . . . . . 12
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)))) | 
| 27 |  | solin 5618 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎𝑅𝑏 ∨ 𝑎 = 𝑏 ∨ 𝑏𝑅𝑎)) | 
| 28 |  | infpr 9544 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑅 Or 𝑉 ∧ 𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → inf({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑎𝑅𝑏, 𝑎, 𝑏)) | 
| 29 | 28 | 3expb 1120 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → inf({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑎𝑅𝑏, 𝑎, 𝑏)) | 
| 30 |  | iftrue 4530 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝑎𝑅𝑏 → if(𝑎𝑅𝑏, 𝑎, 𝑏) = 𝑎) | 
| 31 | 29, 30 | sylan9eqr 2798 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → inf({𝑎, 𝑏}, 𝑉, 𝑅) = 𝑎) | 
| 32 | 31 | eqeq2d 2747 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ↔ inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎)) | 
| 33 |  | suppr 9512 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑅 Or 𝑉 ∧ 𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) → sup({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑏𝑅𝑎, 𝑎, 𝑏)) | 
| 34 | 33 | 3expb 1120 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → sup({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑏𝑅𝑎, 𝑎, 𝑏)) | 
| 35 | 34 | adantl 481 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → sup({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑏𝑅𝑎, 𝑎, 𝑏)) | 
| 36 |  | sotric 5621 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎𝑅𝑏 ↔ ¬ (𝑎 = 𝑏 ∨ 𝑏𝑅𝑎))) | 
| 37 |  | ioran 985 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (¬
(𝑎 = 𝑏 ∨ 𝑏𝑅𝑎) ↔ (¬ 𝑎 = 𝑏 ∧ ¬ 𝑏𝑅𝑎)) | 
| 38 |  | iffalse 4533 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (¬
𝑏𝑅𝑎 → if(𝑏𝑅𝑎, 𝑎, 𝑏) = 𝑏) | 
| 39 | 37, 38 | simplbiim 504 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ (¬
(𝑎 = 𝑏 ∨ 𝑏𝑅𝑎) → if(𝑏𝑅𝑎, 𝑎, 𝑏) = 𝑏) | 
| 40 | 36, 39 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎𝑅𝑏 → if(𝑏𝑅𝑎, 𝑎, 𝑏) = 𝑏)) | 
| 41 | 40 | impcom 407 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → if(𝑏𝑅𝑎, 𝑎, 𝑏) = 𝑏) | 
| 42 | 35, 41 | eqtrd 2776 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → sup({𝑎, 𝑏}, 𝑉, 𝑅) = 𝑏) | 
| 43 | 42 | eqeq2d 2747 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅) ↔ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏)) | 
| 44 | 32, 43 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏))) | 
| 45 | 44 | adantr 480 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏))) | 
| 46 |  | solin 5618 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑅 Or 𝑉 ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → (𝑐𝑅𝑑 ∨ 𝑐 = 𝑑 ∨ 𝑑𝑅𝑐)) | 
| 47 | 46 | adantrr 717 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑐𝑅𝑑 ∨ 𝑐 = 𝑑 ∨ 𝑑𝑅𝑐)) | 
| 48 |  | simpl 482 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → 𝑅 Or 𝑉) | 
| 49 |  | simprll 778 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → 𝑐 ∈ 𝑉) | 
| 50 |  | simprlr 779 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → 𝑑 ∈ 𝑉) | 
| 51 |  | infpr 9544 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ 𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) → inf({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑐𝑅𝑑, 𝑐, 𝑑)) | 
| 52 | 48, 49, 50, 51 | syl3anc 1372 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → inf({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑐𝑅𝑑, 𝑐, 𝑑)) | 
| 53 |  | iftrue 4530 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ (𝑐𝑅𝑑 → if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑐) | 
| 54 | 52, 53 | sylan9eqr 2798 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑐) | 
| 55 | 54 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ↔ 𝑐 = 𝑎)) | 
| 56 |  | suppr 9512 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ ((𝑅 Or 𝑉 ∧ 𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) → sup({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑑𝑅𝑐, 𝑐, 𝑑)) | 
| 57 | 48, 49, 50, 56 | syl3anc 1372 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → sup({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑑𝑅𝑐, 𝑐, 𝑑)) | 
| 58 | 57 | adantl 481 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → sup({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑑𝑅𝑐, 𝑐, 𝑑)) | 
| 59 |  | sotric 5621 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ ((𝑅 Or 𝑉 ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → (𝑐𝑅𝑑 ↔ ¬ (𝑐 = 𝑑 ∨ 𝑑𝑅𝑐))) | 
| 60 | 59 | adantrr 717 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑐𝑅𝑑 ↔ ¬ (𝑐 = 𝑑 ∨ 𝑑𝑅𝑐))) | 
| 61 |  | ioran 985 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (¬
(𝑐 = 𝑑 ∨ 𝑑𝑅𝑐) ↔ (¬ 𝑐 = 𝑑 ∧ ¬ 𝑑𝑅𝑐)) | 
| 62 |  | iffalse 4533 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (¬
𝑑𝑅𝑐 → if(𝑑𝑅𝑐, 𝑐, 𝑑) = 𝑑) | 
| 63 | 61, 62 | simplbiim 504 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ (¬
(𝑐 = 𝑑 ∨ 𝑑𝑅𝑐) → if(𝑑𝑅𝑐, 𝑐, 𝑑) = 𝑑) | 
| 64 | 60, 63 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑐𝑅𝑑 → if(𝑑𝑅𝑐, 𝑐, 𝑑) = 𝑑)) | 
| 65 | 64 | impcom 407 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → if(𝑑𝑅𝑐, 𝑐, 𝑑) = 𝑑) | 
| 66 | 58, 65 | eqtrd 2776 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑑) | 
| 67 | 66 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ↔ 𝑑 = 𝑏)) | 
| 68 | 55, 67 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) ↔ (𝑐 = 𝑎 ∧ 𝑑 = 𝑏))) | 
| 69 |  | orc 867 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 70 | 68, 69 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 71 | 70 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑐𝑅𝑑 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 72 |  | eqneqall 2950 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (𝑐 = 𝑑 → (𝑐 ≠ 𝑑 → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 73 | 72 | adantld 490 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ (𝑐 = 𝑑 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 74 | 73 | adantld 490 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑐 = 𝑑 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 75 | 52 | adantl 481 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → inf({𝑐, 𝑑}, 𝑉, 𝑅) = if(𝑐𝑅𝑑, 𝑐, 𝑑)) | 
| 76 | 75 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ↔ if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎)) | 
| 77 |  | iftrue 4530 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ (𝑑𝑅𝑐 → if(𝑑𝑅𝑐, 𝑐, 𝑑) = 𝑐) | 
| 78 | 57, 77 | sylan9eqr 2798 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑐) | 
| 79 | 78 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ↔ 𝑐 = 𝑏)) | 
| 80 | 76, 79 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) ↔ (if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ∧ 𝑐 = 𝑏))) | 
| 81 |  | simpl 482 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) | 
| 82 | 81 | ancomd 461 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → (𝑑 ∈ 𝑉 ∧ 𝑐 ∈ 𝑉)) | 
| 83 |  | sotric 5621 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ ((𝑅 Or 𝑉 ∧ (𝑑 ∈ 𝑉 ∧ 𝑐 ∈ 𝑉)) → (𝑑𝑅𝑐 ↔ ¬ (𝑑 = 𝑐 ∨ 𝑐𝑅𝑑))) | 
| 84 | 82, 83 | sylan2 593 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑑𝑅𝑐 ↔ ¬ (𝑑 = 𝑐 ∨ 𝑐𝑅𝑑))) | 
| 85 |  | ioran 985 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (¬
(𝑑 = 𝑐 ∨ 𝑐𝑅𝑑) ↔ (¬ 𝑑 = 𝑐 ∧ ¬ 𝑐𝑅𝑑)) | 
| 86 |  | iffalse 4533 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . 37
⊢ (¬
𝑐𝑅𝑑 → if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑑) | 
| 87 | 85, 86 | simplbiim 504 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . 36
⊢ (¬
(𝑑 = 𝑐 ∨ 𝑐𝑅𝑑) → if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑑) | 
| 88 | 87 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ (¬
(𝑑 = 𝑐 ∨ 𝑐𝑅𝑑) → (if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ↔ 𝑑 = 𝑎)) | 
| 89 | 84, 88 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑑𝑅𝑐 → (if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ↔ 𝑑 = 𝑎))) | 
| 90 | 89 | impcom 407 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ↔ 𝑑 = 𝑎)) | 
| 91 | 90 | anbi1d 631 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ∧ 𝑐 = 𝑏) ↔ (𝑑 = 𝑎 ∧ 𝑐 = 𝑏))) | 
| 92 |  | olc 868 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑐 = 𝑏 ∧ 𝑑 = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 93 | 92 | ancoms 458 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑 = 𝑎 ∧ 𝑐 = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 94 | 91, 93 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑎 ∧ 𝑐 = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 95 | 80, 94 | sylbid 240 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 96 | 95 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑑𝑅𝑐 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 97 | 71, 74, 96 | 3jaoi 1429 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑐𝑅𝑑 ∨ 𝑐 = 𝑑 ∨ 𝑑𝑅𝑐) → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 98 | 47, 97 | mpcom 38 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 99 | 98 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ (𝑅 Or 𝑉 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 100 | 99 | ad2antrl 728 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 101 | 100 | imp 406 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 102 | 45, 101 | sylbid 240 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ (((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 103 | 102 | ex 412 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 104 | 103 | a1d 25 | . . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝑎𝑅𝑏 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))))) | 
| 105 | 104 | ex 412 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎𝑅𝑏 → ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))))) | 
| 106 |  | eqneqall 2950 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑎 = 𝑏 → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))))) | 
| 107 | 106 | a1d 25 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎 = 𝑏 → ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))))) | 
| 108 | 29 | adantl 481 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → inf({𝑎, 𝑏}, 𝑉, 𝑅) = if(𝑎𝑅𝑏, 𝑎, 𝑏)) | 
| 109 |  | sotric 5621 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑅 Or 𝑉 ∧ (𝑏 ∈ 𝑉 ∧ 𝑎 ∈ 𝑉)) → (𝑏𝑅𝑎 ↔ ¬ (𝑏 = 𝑎 ∨ 𝑎𝑅𝑏))) | 
| 110 | 109 | ancom2s 650 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑏𝑅𝑎 ↔ ¬ (𝑏 = 𝑎 ∨ 𝑎𝑅𝑏))) | 
| 111 |  | ioran 985 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (¬
(𝑏 = 𝑎 ∨ 𝑎𝑅𝑏) ↔ (¬ 𝑏 = 𝑎 ∧ ¬ 𝑎𝑅𝑏)) | 
| 112 |  | iffalse 4533 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (¬
𝑎𝑅𝑏 → if(𝑎𝑅𝑏, 𝑎, 𝑏) = 𝑏) | 
| 113 | 111, 112 | simplbiim 504 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ (¬
(𝑏 = 𝑎 ∨ 𝑎𝑅𝑏) → if(𝑎𝑅𝑏, 𝑎, 𝑏) = 𝑏) | 
| 114 | 110, 113 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑏𝑅𝑎 → if(𝑎𝑅𝑏, 𝑎, 𝑏) = 𝑏)) | 
| 115 | 114 | impcom 407 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → if(𝑎𝑅𝑏, 𝑎, 𝑏) = 𝑏) | 
| 116 | 108, 115 | eqtrd 2776 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → inf({𝑎, 𝑏}, 𝑉, 𝑅) = 𝑏) | 
| 117 | 116 | eqeq2d 2747 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ↔ inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏)) | 
| 118 |  | iftrue 4530 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝑏𝑅𝑎 → if(𝑏𝑅𝑎, 𝑎, 𝑏) = 𝑎) | 
| 119 | 34, 118 | sylan9eqr 2798 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → sup({𝑎, 𝑏}, 𝑉, 𝑅) = 𝑎) | 
| 120 | 119 | eqeq2d 2747 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅) ↔ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎)) | 
| 121 | 117, 120 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎))) | 
| 122 | 121 | adantr 480 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) ↔ (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎))) | 
| 123 | 54 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ↔ 𝑐 = 𝑏)) | 
| 124 | 66 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ↔ 𝑑 = 𝑎)) | 
| 125 | 123, 124 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) ↔ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 126 | 125, 92 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑐𝑅𝑑 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 127 | 126 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑐𝑅𝑑 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 128 |  | eqneqall 2950 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ (𝑐 = 𝑑 → (𝑐 ≠ 𝑑 → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 129 | 128 | adantld 490 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ (𝑐 = 𝑑 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 130 | 129 | adantld 490 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑐 = 𝑑 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 131 | 84, 87 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 35
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → (𝑑𝑅𝑐 → if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑑)) | 
| 132 | 131 | impcom 407 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → if(𝑐𝑅𝑑, 𝑐, 𝑑) = 𝑑) | 
| 133 | 75, 132 | eqtrd 2776 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑑) | 
| 134 | 133 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ↔ 𝑑 = 𝑏)) | 
| 135 | 78 | eqeq1d 2738 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → (sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎 ↔ 𝑐 = 𝑎)) | 
| 136 | 134, 135 | anbi12d 632 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) ↔ (𝑑 = 𝑏 ∧ 𝑐 = 𝑎))) | 
| 137 | 69 | ancoms 458 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
⊢ ((𝑑 = 𝑏 ∧ 𝑐 = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 138 | 136, 137 | biimtrdi 253 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
⊢ ((𝑑𝑅𝑐 ∧ (𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑))) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 139 | 138 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑑𝑅𝑐 → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 140 | 127, 130,
139 | 3jaoi 1429 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((𝑐𝑅𝑑 ∨ 𝑐 = 𝑑 ∨ 𝑑𝑅𝑐) → ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 141 | 47, 140 | mpcom 38 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑅 Or 𝑉 ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 142 | 141 | ex 412 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ (𝑅 Or 𝑉 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 143 | 142 | ad2antrl 728 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 144 | 143 | imp 406 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑏 ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = 𝑎) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 145 | 122, 144 | sylbid 240 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ (((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) ∧ ((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 146 | 145 | ex 412 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 147 | 146 | a1d 25 | . . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝑏𝑅𝑎 ∧ (𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉))) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))))) | 
| 148 | 147 | ex 412 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑏𝑅𝑎 → ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))))) | 
| 149 | 105, 107,
148 | 3jaoi 1429 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝑎𝑅𝑏 ∨ 𝑎 = 𝑏 ∨ 𝑏𝑅𝑎) → ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))))) | 
| 150 | 27, 149 | mpcom 38 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → (𝑎 ≠ 𝑏 → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))))) | 
| 151 | 150 | adantld 490 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ((𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))))) | 
| 152 | 151 | imp 406 | . . . . . . . . . . . . . . . 16
⊢ (((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) → (((𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉) ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 153 | 152 | expdimp 452 | . . . . . . . . . . . . . . 15
⊢ ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → (𝑐 ≠ 𝑑 → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 154 | 153 | adantld 490 | . . . . . . . . . . . . . 14
⊢ ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → ((𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))))) | 
| 155 | 154 | imp 406 | . . . . . . . . . . . . 13
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎)))) | 
| 156 |  | vex 3483 | . . . . . . . . . . . . . 14
⊢ 𝑐 ∈ V | 
| 157 |  | vex 3483 | . . . . . . . . . . . . . 14
⊢ 𝑑 ∈ V | 
| 158 |  | vex 3483 | . . . . . . . . . . . . . 14
⊢ 𝑎 ∈ V | 
| 159 |  | vex 3483 | . . . . . . . . . . . . . 14
⊢ 𝑏 ∈ V | 
| 160 | 156, 157,
158, 159 | preq12b 4849 | . . . . . . . . . . . . 13
⊢ ({𝑐, 𝑑} = {𝑎, 𝑏} ↔ ((𝑐 = 𝑎 ∧ 𝑑 = 𝑏) ∨ (𝑐 = 𝑏 ∧ 𝑑 = 𝑎))) | 
| 161 | 155, 160 | imbitrrdi 252 | . . . . . . . . . . . 12
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → ((inf({𝑐, 𝑑}, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅) ∧ sup({𝑐, 𝑑}, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) → {𝑐, 𝑑} = {𝑎, 𝑏})) | 
| 162 | 26, 161 | sylbid 240 | . . . . . . . . . . 11
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})) | 
| 163 |  | infeq1 9517 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑍 = {𝑐, 𝑑} → inf(𝑍, 𝑉, 𝑅) = inf({𝑐, 𝑑}, 𝑉, 𝑅)) | 
| 164 |  | supeq1 9486 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑍 = {𝑐, 𝑑} → sup(𝑍, 𝑉, 𝑅) = sup({𝑐, 𝑑}, 𝑉, 𝑅)) | 
| 165 | 163, 164 | opeq12d 4880 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑍 = {𝑐, 𝑑} → 〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉) | 
| 166 |  | infeq1 9517 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑊 = {𝑎, 𝑏} → inf(𝑊, 𝑉, 𝑅) = inf({𝑎, 𝑏}, 𝑉, 𝑅)) | 
| 167 |  | supeq1 9486 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑊 = {𝑎, 𝑏} → sup(𝑊, 𝑉, 𝑅) = sup({𝑎, 𝑏}, 𝑉, 𝑅)) | 
| 168 | 166, 167 | opeq12d 4880 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑊 = {𝑎, 𝑏} → 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉) | 
| 169 | 165, 168 | eqeqan12rd 2751 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝑊 = {𝑎, 𝑏} ∧ 𝑍 = {𝑐, 𝑑}) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 ↔ 〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉)) | 
| 170 |  | eqeq12 2753 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝑍 = {𝑐, 𝑑} ∧ 𝑊 = {𝑎, 𝑏}) → (𝑍 = 𝑊 ↔ {𝑐, 𝑑} = {𝑎, 𝑏})) | 
| 171 | 170 | ancoms 458 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝑊 = {𝑎, 𝑏} ∧ 𝑍 = {𝑐, 𝑑}) → (𝑍 = 𝑊 ↔ {𝑐, 𝑑} = {𝑎, 𝑏})) | 
| 172 | 169, 171 | imbi12d 344 | . . . . . . . . . . . . . . . . 17
⊢ ((𝑊 = {𝑎, 𝑏} ∧ 𝑍 = {𝑐, 𝑑}) → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏}))) | 
| 173 | 172 | ex 412 | . . . . . . . . . . . . . . . 16
⊢ (𝑊 = {𝑎, 𝑏} → (𝑍 = {𝑐, 𝑑} → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})))) | 
| 174 | 173 | ad2antrl 728 | . . . . . . . . . . . . . . 15
⊢ (((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) → (𝑍 = {𝑐, 𝑑} → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})))) | 
| 175 | 174 | adantr 480 | . . . . . . . . . . . . . 14
⊢ ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → (𝑍 = {𝑐, 𝑑} → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})))) | 
| 176 | 175 | com12 32 | . . . . . . . . . . . . 13
⊢ (𝑍 = {𝑐, 𝑑} → ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})))) | 
| 177 | 176 | adantr 480 | . . . . . . . . . . . 12
⊢ ((𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏})))) | 
| 178 | 177 | impcom 407 | . . . . . . . . . . 11
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → ((〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊) ↔ (〈inf({𝑐, 𝑑}, 𝑉, 𝑅), sup({𝑐, 𝑑}, 𝑉, 𝑅)〉 = 〈inf({𝑎, 𝑏}, 𝑉, 𝑅), sup({𝑎, 𝑏}, 𝑉, 𝑅)〉 → {𝑐, 𝑑} = {𝑎, 𝑏}))) | 
| 179 | 162, 178 | mpbird 257 | . . . . . . . . . 10
⊢
(((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) ∧ (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑)) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)) | 
| 180 | 179 | ex 412 | . . . . . . . . 9
⊢ ((((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) ∧ (𝑐 ∈ 𝑉 ∧ 𝑑 ∈ 𝑉)) → ((𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊))) | 
| 181 | 180 | rexlimdvva 3212 | . . . . . . . 8
⊢ (((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) ∧ (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏)) → (∃𝑐 ∈ 𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊))) | 
| 182 | 181 | ex 412 | . . . . . . 7
⊢ ((𝑅 Or 𝑉 ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) → ((𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏) → (∃𝑐 ∈ 𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)))) | 
| 183 | 182 | rexlimdvva 3212 | . . . . . 6
⊢ (𝑅 Or 𝑉 → (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏) → (∃𝑐 ∈ 𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)))) | 
| 184 | 183 | com13 88 | . . . . 5
⊢
(∃𝑐 ∈
𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 (𝑊 = {𝑎, 𝑏} ∧ 𝑎 ≠ 𝑏) → (𝑅 Or 𝑉 → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)))) | 
| 185 | 19, 184 | biimtrid 242 | . . . 4
⊢
(∃𝑐 ∈
𝑉 ∃𝑑 ∈ 𝑉 (𝑍 = {𝑐, 𝑑} ∧ 𝑐 ≠ 𝑑) → (𝑊 ∈ 𝑃 → (𝑅 Or 𝑉 → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)))) | 
| 186 | 18, 185 | sylbi 217 | . . 3
⊢ (𝑍 ∈ 𝑃 → (𝑊 ∈ 𝑃 → (𝑅 Or 𝑉 → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)))) | 
| 187 | 186 | 3imp31 1111 | . 2
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → (〈inf(𝑍, 𝑉, 𝑅), sup(𝑍, 𝑉, 𝑅)〉 = 〈inf(𝑊, 𝑉, 𝑅), sup(𝑊, 𝑉, 𝑅)〉 → 𝑍 = 𝑊)) | 
| 188 | 16, 187 | sylbid 240 | 1
⊢ ((𝑅 Or 𝑉 ∧ 𝑊 ∈ 𝑃 ∧ 𝑍 ∈ 𝑃) → ((𝐹‘𝑍) = (𝐹‘𝑊) → 𝑍 = 𝑊)) |