| Step | Hyp | Ref
 | Expression | 
| 1 |   | mapssbi.b | 
. . . . 5
⊢ (𝜑 → 𝐵 ∈ 𝑊) | 
| 2 | 1 | adantr 480 | 
. . . 4
⊢ ((𝜑 ∧ 𝐴 ⊆ 𝐵) → 𝐵 ∈ 𝑊) | 
| 3 |   | simpr 484 | 
. . . 4
⊢ ((𝜑 ∧ 𝐴 ⊆ 𝐵) → 𝐴 ⊆ 𝐵) | 
| 4 |   | mapss 8910 | 
. . . 4
⊢ ((𝐵 ∈ 𝑊 ∧ 𝐴 ⊆ 𝐵) → (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 5 | 2, 3, 4 | syl2anc 584 | 
. . 3
⊢ ((𝜑 ∧ 𝐴 ⊆ 𝐵) → (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 6 | 5 | ex 412 | 
. 2
⊢ (𝜑 → (𝐴 ⊆ 𝐵 → (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶))) | 
| 7 |   | simplr 768 | 
. . . 4
⊢ (((𝜑 ∧ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) ∧ ¬ 𝐴 ⊆ 𝐵) → (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 8 |   | nssrex 45024 | 
. . . . . . . 8
⊢ (¬
𝐴 ⊆ 𝐵 ↔ ∃𝑥 ∈ 𝐴 ¬ 𝑥 ∈ 𝐵) | 
| 9 | 8 | biimpi 216 | 
. . . . . . 7
⊢ (¬
𝐴 ⊆ 𝐵 → ∃𝑥 ∈ 𝐴 ¬ 𝑥 ∈ 𝐵) | 
| 10 | 9 | adantl 481 | 
. . . . . 6
⊢ ((𝜑 ∧ ¬ 𝐴 ⊆ 𝐵) → ∃𝑥 ∈ 𝐴 ¬ 𝑥 ∈ 𝐵) | 
| 11 |   | fconst6g 6776 | 
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ 𝐴 → (𝐶 × {𝑥}):𝐶⟶𝐴) | 
| 12 | 11 | adantl 481 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝐶 × {𝑥}):𝐶⟶𝐴) | 
| 13 |   | mapssbi.a | 
. . . . . . . . . . . . . 14
⊢ (𝜑 → 𝐴 ∈ 𝑉) | 
| 14 |   | mapssbi.c | 
. . . . . . . . . . . . . 14
⊢ (𝜑 → 𝐶 ∈ 𝑍) | 
| 15 |   | elmapg 8860 | 
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑍) → ((𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶) ↔ (𝐶 × {𝑥}):𝐶⟶𝐴)) | 
| 16 | 13, 14, 15 | syl2anc 584 | 
. . . . . . . . . . . . 13
⊢ (𝜑 → ((𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶) ↔ (𝐶 × {𝑥}):𝐶⟶𝐴)) | 
| 17 | 16 | adantr 480 | 
. . . . . . . . . . . 12
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → ((𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶) ↔ (𝐶 × {𝑥}):𝐶⟶𝐴)) | 
| 18 | 12, 17 | mpbird 257 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → (𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶)) | 
| 19 | 18 | 3adant3 1132 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ ¬ 𝑥 ∈ 𝐵) → (𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶)) | 
| 20 | 14 | adantr 480 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → 𝐶 ∈ 𝑍) | 
| 21 | 1 | adantr 480 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → 𝐵 ∈ 𝑊) | 
| 22 |   | mapssbi.n | 
. . . . . . . . . . . . . . 15
⊢ (𝜑 → 𝐶 ≠ ∅) | 
| 23 | 22 | adantr 480 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → 𝐶 ≠ ∅) | 
| 24 |   | simpr 484 | 
. . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) | 
| 25 | 20, 21, 23, 24 | snelmap 45020 | 
. . . . . . . . . . . . 13
⊢ ((𝜑 ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → 𝑥 ∈ 𝐵) | 
| 26 | 25 | adantlr 715 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ¬ 𝑥 ∈ 𝐵) ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → 𝑥 ∈ 𝐵) | 
| 27 |   | simplr 768 | 
. . . . . . . . . . . 12
⊢ (((𝜑 ∧ ¬ 𝑥 ∈ 𝐵) ∧ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → ¬ 𝑥 ∈ 𝐵) | 
| 28 | 26, 27 | pm2.65da 816 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ ¬ 𝑥 ∈ 𝐵) → ¬ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) | 
| 29 | 28 | 3adant2 1131 | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ ¬ 𝑥 ∈ 𝐵) → ¬ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) | 
| 30 |   | nelss 4029 | 
. . . . . . . . . 10
⊢ (((𝐶 × {𝑥}) ∈ (𝐴 ↑m 𝐶) ∧ ¬ (𝐶 × {𝑥}) ∈ (𝐵 ↑m 𝐶)) → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 31 | 19, 29, 30 | syl2anc 584 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴 ∧ ¬ 𝑥 ∈ 𝐵) → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 32 | 31 | 3exp 1119 | 
. . . . . . . 8
⊢ (𝜑 → (𝑥 ∈ 𝐴 → (¬ 𝑥 ∈ 𝐵 → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)))) | 
| 33 | 32 | adantr 480 | 
. . . . . . 7
⊢ ((𝜑 ∧ ¬ 𝐴 ⊆ 𝐵) → (𝑥 ∈ 𝐴 → (¬ 𝑥 ∈ 𝐵 → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)))) | 
| 34 | 33 | rexlimdv 3140 | 
. . . . . 6
⊢ ((𝜑 ∧ ¬ 𝐴 ⊆ 𝐵) → (∃𝑥 ∈ 𝐴 ¬ 𝑥 ∈ 𝐵 → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶))) | 
| 35 | 10, 34 | mpd 15 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐴 ⊆ 𝐵) → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 36 | 35 | adantlr 715 | 
. . . 4
⊢ (((𝜑 ∧ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) ∧ ¬ 𝐴 ⊆ 𝐵) → ¬ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) | 
| 37 | 7, 36 | condan 817 | 
. . 3
⊢ ((𝜑 ∧ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶)) → 𝐴 ⊆ 𝐵) | 
| 38 | 37 | ex 412 | 
. 2
⊢ (𝜑 → ((𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶) → 𝐴 ⊆ 𝐵)) | 
| 39 | 6, 38 | impbid 212 | 
1
⊢ (𝜑 → (𝐴 ⊆ 𝐵 ↔ (𝐴 ↑m 𝐶) ⊆ (𝐵 ↑m 𝐶))) |