Proof of Theorem fnejoin2
| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | unisng 4924 | . . . . . . . . 9
⊢ (𝑋 ∈ 𝑉 → ∪ {𝑋} = 𝑋) | 
| 2 | 1 | eqcomd 2742 | . . . . . . . 8
⊢ (𝑋 ∈ 𝑉 → 𝑋 = ∪ {𝑋}) | 
| 3 | 2 | adantr 480 | . . . . . . 7
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → 𝑋 = ∪ {𝑋}) | 
| 4 |  | iftrue 4530 | . . . . . . . . 9
⊢ (𝑆 = ∅ → if(𝑆 = ∅, {𝑋}, ∪ 𝑆) = {𝑋}) | 
| 5 | 4 | unieqd 4919 | . . . . . . . 8
⊢ (𝑆 = ∅ → ∪ if(𝑆
= ∅, {𝑋}, ∪ 𝑆) =
∪ {𝑋}) | 
| 6 | 5 | eqeq2d 2747 | . . . . . . 7
⊢ (𝑆 = ∅ → (𝑋 = ∪
if(𝑆 = ∅, {𝑋}, ∪
𝑆) ↔ 𝑋 = ∪ {𝑋})) | 
| 7 | 3, 6 | syl5ibrcom 247 | . . . . . 6
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (𝑆 = ∅ → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆))) | 
| 8 |  | n0 4352 | . . . . . . 7
⊢ (𝑆 ≠ ∅ ↔
∃𝑥 𝑥 ∈ 𝑆) | 
| 9 |  | unieq 4917 | . . . . . . . . . . . . 13
⊢ (𝑦 = 𝑥 → ∪ 𝑦 = ∪
𝑥) | 
| 10 | 9 | eqeq2d 2747 | . . . . . . . . . . . 12
⊢ (𝑦 = 𝑥 → (𝑋 = ∪ 𝑦 ↔ 𝑋 = ∪ 𝑥)) | 
| 11 | 10 | rspccva 3620 | . . . . . . . . . . 11
⊢
((∀𝑦 ∈
𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → 𝑋 = ∪ 𝑥) | 
| 12 | 11 | 3adant1 1130 | . . . . . . . . . 10
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → 𝑋 = ∪ 𝑥) | 
| 13 |  | fnejoin1 36370 | . . . . . . . . . . 11
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → 𝑥Fneif(𝑆 = ∅, {𝑋}, ∪ 𝑆)) | 
| 14 |  | eqid 2736 | . . . . . . . . . . . 12
⊢ ∪ 𝑥 =
∪ 𝑥 | 
| 15 |  | eqid 2736 | . . . . . . . . . . . 12
⊢ ∪ if(𝑆
= ∅, {𝑋}, ∪ 𝑆) =
∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆) | 
| 16 | 14, 15 | fnebas 36346 | . . . . . . . . . . 11
⊢ (𝑥Fneif(𝑆 = ∅, {𝑋}, ∪ 𝑆) → ∪ 𝑥 =
∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)) | 
| 17 | 13, 16 | syl 17 | . . . . . . . . . 10
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → ∪ 𝑥 = ∪
if(𝑆 = ∅, {𝑋}, ∪
𝑆)) | 
| 18 | 12, 17 | eqtrd 2776 | . . . . . . . . 9
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)) | 
| 19 | 18 | 3expia 1121 | . . . . . . . 8
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (𝑥 ∈ 𝑆 → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆))) | 
| 20 | 19 | exlimdv 1932 | . . . . . . 7
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (∃𝑥 𝑥 ∈ 𝑆 → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆))) | 
| 21 | 8, 20 | biimtrid 242 | . . . . . 6
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (𝑆 ≠ ∅ → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆))) | 
| 22 | 7, 21 | pm2.61dne 3027 | . . . . 5
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)) | 
| 23 |  | eqid 2736 | . . . . . 6
⊢ ∪ 𝑇 =
∪ 𝑇 | 
| 24 | 15, 23 | fnebas 36346 | . . . . 5
⊢ (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → ∪
if(𝑆 = ∅, {𝑋}, ∪
𝑆) = ∪ 𝑇) | 
| 25 | 22, 24 | sylan9eq 2796 | . . . 4
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇) → 𝑋 = ∪ 𝑇) | 
| 26 | 25 | ex 412 | . . 3
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → 𝑋 = ∪ 𝑇)) | 
| 27 |  | fnetr 36353 | . . . . . . 7
⊢ ((𝑥Fneif(𝑆 = ∅, {𝑋}, ∪ 𝑆) ∧ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇) → 𝑥Fne𝑇) | 
| 28 | 27 | ex 412 | . . . . . 6
⊢ (𝑥Fneif(𝑆 = ∅, {𝑋}, ∪ 𝑆) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → 𝑥Fne𝑇)) | 
| 29 | 13, 28 | syl 17 | . . . . 5
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦 ∧ 𝑥 ∈ 𝑆) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → 𝑥Fne𝑇)) | 
| 30 | 29 | 3expa 1118 | . . . 4
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ 𝑥 ∈ 𝑆) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → 𝑥Fne𝑇)) | 
| 31 | 30 | ralrimdva 3153 | . . 3
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) | 
| 32 | 26, 31 | jcad 512 | . 2
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 → (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇))) | 
| 33 | 22 | adantr 480 | . . . . 5
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → 𝑋 = ∪ if(𝑆 = ∅, {𝑋}, ∪ 𝑆)) | 
| 34 |  | simprl 770 | . . . . 5
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → 𝑋 = ∪ 𝑇) | 
| 35 | 33, 34 | eqtr3d 2778 | . . . 4
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → ∪
if(𝑆 = ∅, {𝑋}, ∪
𝑆) = ∪ 𝑇) | 
| 36 |  | sseq1 4008 | . . . . 5
⊢ ({𝑋} = if(𝑆 = ∅, {𝑋}, ∪ 𝑆) → ({𝑋} ⊆ (topGen‘𝑇) ↔ if(𝑆 = ∅, {𝑋}, ∪ 𝑆) ⊆ (topGen‘𝑇))) | 
| 37 |  | sseq1 4008 | . . . . 5
⊢ (∪ 𝑆 =
if(𝑆 = ∅, {𝑋}, ∪
𝑆) → (∪ 𝑆
⊆ (topGen‘𝑇)
↔ if(𝑆 = ∅,
{𝑋}, ∪ 𝑆)
⊆ (topGen‘𝑇))) | 
| 38 |  | elex 3500 | . . . . . . . . . . . 12
⊢ (𝑋 ∈ 𝑉 → 𝑋 ∈ V) | 
| 39 | 38 | ad2antrr 726 | . . . . . . . . . . 11
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → 𝑋 ∈ V) | 
| 40 | 34, 39 | eqeltrrd 2841 | . . . . . . . . . 10
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → ∪ 𝑇 ∈ V) | 
| 41 |  | uniexb 7785 | . . . . . . . . . 10
⊢ (𝑇 ∈ V ↔ ∪ 𝑇
∈ V) | 
| 42 | 40, 41 | sylibr 234 | . . . . . . . . 9
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → 𝑇 ∈ V) | 
| 43 |  | ssid 4005 | . . . . . . . . 9
⊢ 𝑇 ⊆ 𝑇 | 
| 44 |  | eltg3i 22969 | . . . . . . . . 9
⊢ ((𝑇 ∈ V ∧ 𝑇 ⊆ 𝑇) → ∪ 𝑇 ∈ (topGen‘𝑇)) | 
| 45 | 42, 43, 44 | sylancl 586 | . . . . . . . 8
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → ∪ 𝑇 ∈ (topGen‘𝑇)) | 
| 46 | 34, 45 | eqeltrd 2840 | . . . . . . 7
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → 𝑋 ∈ (topGen‘𝑇)) | 
| 47 | 46 | snssd 4808 | . . . . . 6
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → {𝑋} ⊆ (topGen‘𝑇)) | 
| 48 | 47 | adantr 480 | . . . . 5
⊢ ((((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) ∧ 𝑆 = ∅) → {𝑋} ⊆ (topGen‘𝑇)) | 
| 49 |  | simplrr 777 | . . . . . . 7
⊢ ((((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) ∧ ¬ 𝑆 = ∅) → ∀𝑥 ∈ 𝑆 𝑥Fne𝑇) | 
| 50 |  | fnetg 36347 | . . . . . . . 8
⊢ (𝑥Fne𝑇 → 𝑥 ⊆ (topGen‘𝑇)) | 
| 51 | 50 | ralimi 3082 | . . . . . . 7
⊢
(∀𝑥 ∈
𝑆 𝑥Fne𝑇 → ∀𝑥 ∈ 𝑆 𝑥 ⊆ (topGen‘𝑇)) | 
| 52 | 49, 51 | syl 17 | . . . . . 6
⊢ ((((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) ∧ ¬ 𝑆 = ∅) → ∀𝑥 ∈ 𝑆 𝑥 ⊆ (topGen‘𝑇)) | 
| 53 |  | unissb 4938 | . . . . . 6
⊢ (∪ 𝑆
⊆ (topGen‘𝑇)
↔ ∀𝑥 ∈
𝑆 𝑥 ⊆ (topGen‘𝑇)) | 
| 54 | 52, 53 | sylibr 234 | . . . . 5
⊢ ((((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) ∧ ¬ 𝑆 = ∅) → ∪ 𝑆
⊆ (topGen‘𝑇)) | 
| 55 | 36, 37, 48, 54 | ifbothda 4563 | . . . 4
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → if(𝑆 = ∅, {𝑋}, ∪ 𝑆) ⊆ (topGen‘𝑇)) | 
| 56 | 15, 23 | isfne4 36342 | . . . 4
⊢ (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 ↔ (∪
if(𝑆 = ∅, {𝑋}, ∪
𝑆) = ∪ 𝑇
∧ if(𝑆 = ∅,
{𝑋}, ∪ 𝑆)
⊆ (topGen‘𝑇))) | 
| 57 | 35, 55, 56 | sylanbrc 583 | . . 3
⊢ (((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) ∧ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇)) → if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇) | 
| 58 | 57 | ex 412 | . 2
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → ((𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇) → if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇)) | 
| 59 | 32, 58 | impbid 212 | 1
⊢ ((𝑋 ∈ 𝑉 ∧ ∀𝑦 ∈ 𝑆 𝑋 = ∪ 𝑦) → (if(𝑆 = ∅, {𝑋}, ∪ 𝑆)Fne𝑇 ↔ (𝑋 = ∪ 𝑇 ∧ ∀𝑥 ∈ 𝑆 𝑥Fne𝑇))) |