Proof of Theorem cnmpt2res
| Step | Hyp | Ref
 | Expression | 
| 1 |   | cnmpt2res.10 | 
. . 3
⊢ (𝜑 → (𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ∈ ((𝐽 ×t 𝑀) Cn 𝐿)) | 
| 2 |   | cnmpt1res.5 | 
. . . . 5
⊢ (𝜑 → 𝑌 ⊆ 𝑋) | 
| 3 |   | cnmpt2res.9 | 
. . . . 5
⊢ (𝜑 → 𝑊 ⊆ 𝑍) | 
| 4 |   | xpss12 4770 | 
. . . . 5
⊢ ((𝑌 ⊆ 𝑋 ∧ 𝑊 ⊆ 𝑍) → (𝑌 × 𝑊) ⊆ (𝑋 × 𝑍)) | 
| 5 | 2, 3, 4 | syl2anc 411 | 
. . . 4
⊢ (𝜑 → (𝑌 × 𝑊) ⊆ (𝑋 × 𝑍)) | 
| 6 |   | cnmpt1res.3 | 
. . . . . 6
⊢ (𝜑 → 𝐽 ∈ (TopOn‘𝑋)) | 
| 7 |   | cnmpt2res.8 | 
. . . . . 6
⊢ (𝜑 → 𝑀 ∈ (TopOn‘𝑍)) | 
| 8 |   | txtopon 14498 | 
. . . . . 6
⊢ ((𝐽 ∈ (TopOn‘𝑋) ∧ 𝑀 ∈ (TopOn‘𝑍)) → (𝐽 ×t 𝑀) ∈ (TopOn‘(𝑋 × 𝑍))) | 
| 9 | 6, 7, 8 | syl2anc 411 | 
. . . . 5
⊢ (𝜑 → (𝐽 ×t 𝑀) ∈ (TopOn‘(𝑋 × 𝑍))) | 
| 10 |   | toponuni 14251 | 
. . . . 5
⊢ ((𝐽 ×t 𝑀) ∈ (TopOn‘(𝑋 × 𝑍)) → (𝑋 × 𝑍) = ∪ (𝐽 ×t 𝑀)) | 
| 11 | 9, 10 | syl 14 | 
. . . 4
⊢ (𝜑 → (𝑋 × 𝑍) = ∪ (𝐽 ×t 𝑀)) | 
| 12 | 5, 11 | sseqtrd 3221 | 
. . 3
⊢ (𝜑 → (𝑌 × 𝑊) ⊆ ∪
(𝐽 ×t
𝑀)) | 
| 13 |   | eqid 2196 | 
. . . 4
⊢ ∪ (𝐽
×t 𝑀) =
∪ (𝐽 ×t 𝑀) | 
| 14 | 13 | cnrest 14471 | 
. . 3
⊢ (((𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ∈ ((𝐽 ×t 𝑀) Cn 𝐿) ∧ (𝑌 × 𝑊) ⊆ ∪
(𝐽 ×t
𝑀)) → ((𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ↾ (𝑌 × 𝑊)) ∈ (((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) Cn 𝐿)) | 
| 15 | 1, 12, 14 | syl2anc 411 | 
. 2
⊢ (𝜑 → ((𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ↾ (𝑌 × 𝑊)) ∈ (((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) Cn 𝐿)) | 
| 16 |   | resmpo 6020 | 
. . 3
⊢ ((𝑌 ⊆ 𝑋 ∧ 𝑊 ⊆ 𝑍) → ((𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ↾ (𝑌 × 𝑊)) = (𝑥 ∈ 𝑌, 𝑦 ∈ 𝑊 ↦ 𝐴)) | 
| 17 | 2, 3, 16 | syl2anc 411 | 
. 2
⊢ (𝜑 → ((𝑥 ∈ 𝑋, 𝑦 ∈ 𝑍 ↦ 𝐴) ↾ (𝑌 × 𝑊)) = (𝑥 ∈ 𝑌, 𝑦 ∈ 𝑊 ↦ 𝐴)) | 
| 18 |   | topontop 14250 | 
. . . . . 6
⊢ (𝐽 ∈ (TopOn‘𝑋) → 𝐽 ∈ Top) | 
| 19 | 6, 18 | syl 14 | 
. . . . 5
⊢ (𝜑 → 𝐽 ∈ Top) | 
| 20 |   | topontop 14250 | 
. . . . . 6
⊢ (𝑀 ∈ (TopOn‘𝑍) → 𝑀 ∈ Top) | 
| 21 | 7, 20 | syl 14 | 
. . . . 5
⊢ (𝜑 → 𝑀 ∈ Top) | 
| 22 |   | toponmax 14261 | 
. . . . . . 7
⊢ (𝐽 ∈ (TopOn‘𝑋) → 𝑋 ∈ 𝐽) | 
| 23 | 6, 22 | syl 14 | 
. . . . . 6
⊢ (𝜑 → 𝑋 ∈ 𝐽) | 
| 24 | 23, 2 | ssexd 4173 | 
. . . . 5
⊢ (𝜑 → 𝑌 ∈ V) | 
| 25 |   | toponmax 14261 | 
. . . . . . 7
⊢ (𝑀 ∈ (TopOn‘𝑍) → 𝑍 ∈ 𝑀) | 
| 26 | 7, 25 | syl 14 | 
. . . . . 6
⊢ (𝜑 → 𝑍 ∈ 𝑀) | 
| 27 | 26, 3 | ssexd 4173 | 
. . . . 5
⊢ (𝜑 → 𝑊 ∈ V) | 
| 28 |   | txrest 14512 | 
. . . . 5
⊢ (((𝐽 ∈ Top ∧ 𝑀 ∈ Top) ∧ (𝑌 ∈ V ∧ 𝑊 ∈ V)) → ((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) = ((𝐽 ↾t 𝑌) ×t (𝑀 ↾t 𝑊))) | 
| 29 | 19, 21, 24, 27, 28 | syl22anc 1250 | 
. . . 4
⊢ (𝜑 → ((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) = ((𝐽 ↾t 𝑌) ×t (𝑀 ↾t 𝑊))) | 
| 30 |   | cnmpt1res.2 | 
. . . . 5
⊢ 𝐾 = (𝐽 ↾t 𝑌) | 
| 31 |   | cnmpt2res.7 | 
. . . . 5
⊢ 𝑁 = (𝑀 ↾t 𝑊) | 
| 32 | 30, 31 | oveq12i 5934 | 
. . . 4
⊢ (𝐾 ×t 𝑁) = ((𝐽 ↾t 𝑌) ×t (𝑀 ↾t 𝑊)) | 
| 33 | 29, 32 | eqtr4di 2247 | 
. . 3
⊢ (𝜑 → ((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) = (𝐾 ×t 𝑁)) | 
| 34 | 33 | oveq1d 5937 | 
. 2
⊢ (𝜑 → (((𝐽 ×t 𝑀) ↾t (𝑌 × 𝑊)) Cn 𝐿) = ((𝐾 ×t 𝑁) Cn 𝐿)) | 
| 35 | 15, 17, 34 | 3eltr3d 2279 | 
1
⊢ (𝜑 → (𝑥 ∈ 𝑌, 𝑦 ∈ 𝑊 ↦ 𝐴) ∈ ((𝐾 ×t 𝑁) Cn 𝐿)) |