| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | ufilfil 23913 | . . 3
⊢ (𝐹 ∈ (UFil‘𝑋) → 𝐹 ∈ (Fil‘𝑋)) | 
| 2 |  | ufilmax 23916 | . . . . 5
⊢ ((𝐹 ∈ (UFil‘𝑋) ∧ 𝑓 ∈ (Fil‘𝑋) ∧ 𝐹 ⊆ 𝑓) → 𝐹 = 𝑓) | 
| 3 | 2 | 3expia 1121 | . . . 4
⊢ ((𝐹 ∈ (UFil‘𝑋) ∧ 𝑓 ∈ (Fil‘𝑋)) → (𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) | 
| 4 | 3 | ralrimiva 3145 | . . 3
⊢ (𝐹 ∈ (UFil‘𝑋) → ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) | 
| 5 | 1, 4 | jca 511 | . 2
⊢ (𝐹 ∈ (UFil‘𝑋) → (𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓))) | 
| 6 |  | simpl 482 | . . 3
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) → 𝐹 ∈ (Fil‘𝑋)) | 
| 7 |  | velpw 4604 | . . . . 5
⊢ (𝑥 ∈ 𝒫 𝑋 ↔ 𝑥 ⊆ 𝑋) | 
| 8 |  | simpll 766 | . . . . . . . . . . . . . . . 16
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝐹 ∈ (Fil‘𝑋)) | 
| 9 |  | vsnex 5433 | . . . . . . . . . . . . . . . 16
⊢ {𝑥} ∈ V | 
| 10 |  | unexg 7764 | . . . . . . . . . . . . . . . 16
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ {𝑥} ∈ V) → (𝐹 ∪ {𝑥}) ∈ V) | 
| 11 | 8, 9, 10 | sylancl 586 | . . . . . . . . . . . . . . 15
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 ∪ {𝑥}) ∈ V) | 
| 12 |  | ssfii 9460 | . . . . . . . . . . . . . . 15
⊢ ((𝐹 ∪ {𝑥}) ∈ V → (𝐹 ∪ {𝑥}) ⊆ (fi‘(𝐹 ∪ {𝑥}))) | 
| 13 | 11, 12 | syl 17 | . . . . . . . . . . . . . 14
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 ∪ {𝑥}) ⊆ (fi‘(𝐹 ∪ {𝑥}))) | 
| 14 |  | filsspw 23860 | . . . . . . . . . . . . . . . . . 18
⊢ (𝐹 ∈ (Fil‘𝑋) → 𝐹 ⊆ 𝒫 𝑋) | 
| 15 | 14 | ad2antrr 726 | . . . . . . . . . . . . . . . . 17
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝐹 ⊆ 𝒫 𝑋) | 
| 16 | 7 | biimpri 228 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑥 ⊆ 𝑋 → 𝑥 ∈ 𝒫 𝑋) | 
| 17 | 16 | ad2antlr 727 | . . . . . . . . . . . . . . . . . 18
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑥 ∈ 𝒫 𝑋) | 
| 18 | 17 | snssd 4808 | . . . . . . . . . . . . . . . . 17
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → {𝑥} ⊆ 𝒫 𝑋) | 
| 19 | 15, 18 | unssd 4191 | . . . . . . . . . . . . . . . 16
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 ∪ {𝑥}) ⊆ 𝒫 𝑋) | 
| 20 |  | ssun2 4178 | . . . . . . . . . . . . . . . . . 18
⊢ {𝑥} ⊆ (𝐹 ∪ {𝑥}) | 
| 21 |  | vex 3483 | . . . . . . . . . . . . . . . . . . 19
⊢ 𝑥 ∈ V | 
| 22 | 21 | snnz 4775 | . . . . . . . . . . . . . . . . . 18
⊢ {𝑥} ≠ ∅ | 
| 23 |  | ssn0 4403 | . . . . . . . . . . . . . . . . . 18
⊢ (({𝑥} ⊆ (𝐹 ∪ {𝑥}) ∧ {𝑥} ≠ ∅) → (𝐹 ∪ {𝑥}) ≠ ∅) | 
| 24 | 20, 22, 23 | mp2an 692 | . . . . . . . . . . . . . . . . 17
⊢ (𝐹 ∪ {𝑥}) ≠ ∅ | 
| 25 | 24 | a1i 11 | . . . . . . . . . . . . . . . 16
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 ∪ {𝑥}) ≠ ∅) | 
| 26 |  | simpr 484 | . . . . . . . . . . . . . . . . . 18
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) | 
| 27 |  | ineq2 4213 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑓 = 𝑥 → (𝑦 ∩ 𝑓) = (𝑦 ∩ 𝑥)) | 
| 28 | 27 | neeq1d 2999 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑓 = 𝑥 → ((𝑦 ∩ 𝑓) ≠ ∅ ↔ (𝑦 ∩ 𝑥) ≠ ∅)) | 
| 29 | 21, 28 | ralsn 4680 | . . . . . . . . . . . . . . . . . . 19
⊢
(∀𝑓 ∈
{𝑥} (𝑦 ∩ 𝑓) ≠ ∅ ↔ (𝑦 ∩ 𝑥) ≠ ∅) | 
| 30 | 29 | ralbii 3092 | . . . . . . . . . . . . . . . . . 18
⊢
(∀𝑦 ∈
𝐹 ∀𝑓 ∈ {𝑥} (𝑦 ∩ 𝑓) ≠ ∅ ↔ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) | 
| 31 | 26, 30 | sylibr 234 | . . . . . . . . . . . . . . . . 17
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → ∀𝑦 ∈ 𝐹 ∀𝑓 ∈ {𝑥} (𝑦 ∩ 𝑓) ≠ ∅) | 
| 32 |  | filfbas 23857 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝐹 ∈ (Fil‘𝑋) → 𝐹 ∈ (fBas‘𝑋)) | 
| 33 | 32 | ad2antrr 726 | . . . . . . . . . . . . . . . . . 18
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝐹 ∈ (fBas‘𝑋)) | 
| 34 |  | simplr 768 | . . . . . . . . . . . . . . . . . . 19
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑥 ⊆ 𝑋) | 
| 35 |  | inss2 4237 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑋 ∩ 𝑥) ⊆ 𝑥 | 
| 36 |  | filtop 23864 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ (𝐹 ∈ (Fil‘𝑋) → 𝑋 ∈ 𝐹) | 
| 37 | 36 | adantr 480 | . . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) → 𝑋 ∈ 𝐹) | 
| 38 |  | ineq1 4212 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ (𝑦 = 𝑋 → (𝑦 ∩ 𝑥) = (𝑋 ∩ 𝑥)) | 
| 39 | 38 | neeq1d 2999 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ (𝑦 = 𝑋 → ((𝑦 ∩ 𝑥) ≠ ∅ ↔ (𝑋 ∩ 𝑥) ≠ ∅)) | 
| 40 | 39 | rspcva 3619 | . . . . . . . . . . . . . . . . . . . . 21
⊢ ((𝑋 ∈ 𝐹 ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝑋 ∩ 𝑥) ≠ ∅) | 
| 41 | 37, 40 | sylan 580 | . . . . . . . . . . . . . . . . . . . 20
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝑋 ∩ 𝑥) ≠ ∅) | 
| 42 |  | ssn0 4403 | . . . . . . . . . . . . . . . . . . . 20
⊢ (((𝑋 ∩ 𝑥) ⊆ 𝑥 ∧ (𝑋 ∩ 𝑥) ≠ ∅) → 𝑥 ≠ ∅) | 
| 43 | 35, 41, 42 | sylancr 587 | . . . . . . . . . . . . . . . . . . 19
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑥 ≠ ∅) | 
| 44 | 36 | ad2antrr 726 | . . . . . . . . . . . . . . . . . . 19
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑋 ∈ 𝐹) | 
| 45 |  | snfbas 23875 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝑥 ⊆ 𝑋 ∧ 𝑥 ≠ ∅ ∧ 𝑋 ∈ 𝐹) → {𝑥} ∈ (fBas‘𝑋)) | 
| 46 | 34, 43, 44, 45 | syl3anc 1372 | . . . . . . . . . . . . . . . . . 18
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → {𝑥} ∈ (fBas‘𝑋)) | 
| 47 |  | fbunfip 23878 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ {𝑥} ∈ (fBas‘𝑋)) → (¬ ∅ ∈
(fi‘(𝐹 ∪ {𝑥})) ↔ ∀𝑦 ∈ 𝐹 ∀𝑓 ∈ {𝑥} (𝑦 ∩ 𝑓) ≠ ∅)) | 
| 48 | 33, 46, 47 | syl2anc 584 | . . . . . . . . . . . . . . . . 17
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (¬ ∅ ∈
(fi‘(𝐹 ∪ {𝑥})) ↔ ∀𝑦 ∈ 𝐹 ∀𝑓 ∈ {𝑥} (𝑦 ∩ 𝑓) ≠ ∅)) | 
| 49 | 31, 48 | mpbird 257 | . . . . . . . . . . . . . . . 16
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → ¬ ∅ ∈
(fi‘(𝐹 ∪ {𝑥}))) | 
| 50 |  | fsubbas 23876 | . . . . . . . . . . . . . . . . 17
⊢ (𝑋 ∈ 𝐹 → ((fi‘(𝐹 ∪ {𝑥})) ∈ (fBas‘𝑋) ↔ ((𝐹 ∪ {𝑥}) ⊆ 𝒫 𝑋 ∧ (𝐹 ∪ {𝑥}) ≠ ∅ ∧ ¬ ∅ ∈
(fi‘(𝐹 ∪ {𝑥}))))) | 
| 51 | 44, 50 | syl 17 | . . . . . . . . . . . . . . . 16
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → ((fi‘(𝐹 ∪ {𝑥})) ∈ (fBas‘𝑋) ↔ ((𝐹 ∪ {𝑥}) ⊆ 𝒫 𝑋 ∧ (𝐹 ∪ {𝑥}) ≠ ∅ ∧ ¬ ∅ ∈
(fi‘(𝐹 ∪ {𝑥}))))) | 
| 52 | 19, 25, 49, 51 | mpbir3and 1342 | . . . . . . . . . . . . . . 15
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (fi‘(𝐹 ∪ {𝑥})) ∈ (fBas‘𝑋)) | 
| 53 |  | ssfg 23881 | . . . . . . . . . . . . . . 15
⊢
((fi‘(𝐹 ∪
{𝑥})) ∈
(fBas‘𝑋) →
(fi‘(𝐹 ∪ {𝑥})) ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))) | 
| 54 | 52, 53 | syl 17 | . . . . . . . . . . . . . 14
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (fi‘(𝐹 ∪ {𝑥})) ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))) | 
| 55 | 13, 54 | sstrd 3993 | . . . . . . . . . . . . 13
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 ∪ {𝑥}) ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))) | 
| 56 | 55 | unssad 4192 | . . . . . . . . . . . 12
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝐹 ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))) | 
| 57 |  | fgcl 23887 | . . . . . . . . . . . . 13
⊢
((fi‘(𝐹 ∪
{𝑥})) ∈
(fBas‘𝑋) →
(𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) ∈ (Fil‘𝑋)) | 
| 58 |  | sseq2 4009 | . . . . . . . . . . . . . . 15
⊢ (𝑓 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → (𝐹 ⊆ 𝑓 ↔ 𝐹 ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))))) | 
| 59 |  | eqeq2 2748 | . . . . . . . . . . . . . . 15
⊢ (𝑓 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → (𝐹 = 𝑓 ↔ 𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))))) | 
| 60 | 58, 59 | imbi12d 344 | . . . . . . . . . . . . . 14
⊢ (𝑓 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → ((𝐹 ⊆ 𝑓 → 𝐹 = 𝑓) ↔ (𝐹 ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → 𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))))) | 
| 61 | 60 | rspcv 3617 | . . . . . . . . . . . . 13
⊢ ((𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) ∈ (Fil‘𝑋) → (∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓) → (𝐹 ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → 𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))))) | 
| 62 | 52, 57, 61 | 3syl 18 | . . . . . . . . . . . 12
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓) → (𝐹 ⊆ (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → 𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))))) | 
| 63 | 56, 62 | mpid 44 | . . . . . . . . . . 11
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓) → 𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))))) | 
| 64 |  | vsnid 4662 | . . . . . . . . . . . . . . 15
⊢ 𝑥 ∈ {𝑥} | 
| 65 | 20, 64 | sselii 3979 | . . . . . . . . . . . . . 14
⊢ 𝑥 ∈ (𝐹 ∪ {𝑥}) | 
| 66 | 65 | a1i 11 | . . . . . . . . . . . . 13
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑥 ∈ (𝐹 ∪ {𝑥})) | 
| 67 | 55, 66 | sseldd 3983 | . . . . . . . . . . . 12
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → 𝑥 ∈ (𝑋filGen(fi‘(𝐹 ∪ {𝑥})))) | 
| 68 |  | eleq2 2829 | . . . . . . . . . . . 12
⊢ (𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → (𝑥 ∈ 𝐹 ↔ 𝑥 ∈ (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))))) | 
| 69 | 67, 68 | syl5ibrcom 247 | . . . . . . . . . . 11
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (𝐹 = (𝑋filGen(fi‘(𝐹 ∪ {𝑥}))) → 𝑥 ∈ 𝐹)) | 
| 70 | 63, 69 | syld 47 | . . . . . . . . . 10
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) → (∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓) → 𝑥 ∈ 𝐹)) | 
| 71 | 70 | impancom 451 | . . . . . . . . 9
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ 𝑥 ⊆ 𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) → (∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅ → 𝑥 ∈ 𝐹)) | 
| 72 | 71 | an32s 652 | . . . . . . . 8
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ⊆ 𝑋) → (∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅ → 𝑥 ∈ 𝐹)) | 
| 73 | 72 | con3d 152 | . . . . . . 7
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ⊆ 𝑋) → (¬ 𝑥 ∈ 𝐹 → ¬ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅)) | 
| 74 |  | rexnal 3099 | . . . . . . . . 9
⊢
(∃𝑦 ∈
𝐹 ¬ (𝑦 ∩ 𝑥) ≠ ∅ ↔ ¬ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅) | 
| 75 |  | nne 2943 | . . . . . . . . . . 11
⊢ (¬
(𝑦 ∩ 𝑥) ≠ ∅ ↔ (𝑦 ∩ 𝑥) = ∅) | 
| 76 |  | filelss 23861 | . . . . . . . . . . . . 13
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑦 ∈ 𝐹) → 𝑦 ⊆ 𝑋) | 
| 77 |  | reldisj 4452 | . . . . . . . . . . . . 13
⊢ (𝑦 ⊆ 𝑋 → ((𝑦 ∩ 𝑥) = ∅ ↔ 𝑦 ⊆ (𝑋 ∖ 𝑥))) | 
| 78 | 76, 77 | syl 17 | . . . . . . . . . . . 12
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑦 ∈ 𝐹) → ((𝑦 ∩ 𝑥) = ∅ ↔ 𝑦 ⊆ (𝑋 ∖ 𝑥))) | 
| 79 |  | difss 4135 | . . . . . . . . . . . . . 14
⊢ (𝑋 ∖ 𝑥) ⊆ 𝑋 | 
| 80 |  | filss 23862 | . . . . . . . . . . . . . . 15
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ (𝑦 ∈ 𝐹 ∧ (𝑋 ∖ 𝑥) ⊆ 𝑋 ∧ 𝑦 ⊆ (𝑋 ∖ 𝑥))) → (𝑋 ∖ 𝑥) ∈ 𝐹) | 
| 81 | 80 | 3exp2 1354 | . . . . . . . . . . . . . 14
⊢ (𝐹 ∈ (Fil‘𝑋) → (𝑦 ∈ 𝐹 → ((𝑋 ∖ 𝑥) ⊆ 𝑋 → (𝑦 ⊆ (𝑋 ∖ 𝑥) → (𝑋 ∖ 𝑥) ∈ 𝐹)))) | 
| 82 | 79, 81 | mpii 46 | . . . . . . . . . . . . 13
⊢ (𝐹 ∈ (Fil‘𝑋) → (𝑦 ∈ 𝐹 → (𝑦 ⊆ (𝑋 ∖ 𝑥) → (𝑋 ∖ 𝑥) ∈ 𝐹))) | 
| 83 | 82 | imp 406 | . . . . . . . . . . . 12
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑦 ∈ 𝐹) → (𝑦 ⊆ (𝑋 ∖ 𝑥) → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 84 | 78, 83 | sylbid 240 | . . . . . . . . . . 11
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑦 ∈ 𝐹) → ((𝑦 ∩ 𝑥) = ∅ → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 85 | 75, 84 | biimtrid 242 | . . . . . . . . . 10
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ 𝑦 ∈ 𝐹) → (¬ (𝑦 ∩ 𝑥) ≠ ∅ → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 86 | 85 | rexlimdva 3154 | . . . . . . . . 9
⊢ (𝐹 ∈ (Fil‘𝑋) → (∃𝑦 ∈ 𝐹 ¬ (𝑦 ∩ 𝑥) ≠ ∅ → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 87 | 74, 86 | biimtrrid 243 | . . . . . . . 8
⊢ (𝐹 ∈ (Fil‘𝑋) → (¬ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅ → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 88 | 87 | ad2antrr 726 | . . . . . . 7
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ⊆ 𝑋) → (¬ ∀𝑦 ∈ 𝐹 (𝑦 ∩ 𝑥) ≠ ∅ → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 89 | 73, 88 | syld 47 | . . . . . 6
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ⊆ 𝑋) → (¬ 𝑥 ∈ 𝐹 → (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 90 | 89 | orrd 863 | . . . . 5
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ⊆ 𝑋) → (𝑥 ∈ 𝐹 ∨ (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 91 | 7, 90 | sylan2b 594 | . . . 4
⊢ (((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) ∧ 𝑥 ∈ 𝒫 𝑋) → (𝑥 ∈ 𝐹 ∨ (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 92 | 91 | ralrimiva 3145 | . . 3
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) → ∀𝑥 ∈ 𝒫 𝑋(𝑥 ∈ 𝐹 ∨ (𝑋 ∖ 𝑥) ∈ 𝐹)) | 
| 93 |  | isufil 23912 | . . 3
⊢ (𝐹 ∈ (UFil‘𝑋) ↔ (𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑥 ∈ 𝒫 𝑋(𝑥 ∈ 𝐹 ∨ (𝑋 ∖ 𝑥) ∈ 𝐹))) | 
| 94 | 6, 92, 93 | sylanbrc 583 | . 2
⊢ ((𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓)) → 𝐹 ∈ (UFil‘𝑋)) | 
| 95 | 5, 94 | impbii 209 | 1
⊢ (𝐹 ∈ (UFil‘𝑋) ↔ (𝐹 ∈ (Fil‘𝑋) ∧ ∀𝑓 ∈ (Fil‘𝑋)(𝐹 ⊆ 𝑓 → 𝐹 = 𝑓))) |