| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | oveq2 7439 | . . . . . 6
⊢ (𝑥 = ∅ → (𝐴 ↑m 𝑥) = (𝐴 ↑m
∅)) | 
| 2 | 1 | fveq2d 6910 | . . . . 5
⊢ (𝑥 = ∅ →
(♯‘(𝐴
↑m 𝑥)) =
(♯‘(𝐴
↑m ∅))) | 
| 3 |  | fveq2 6906 | . . . . . 6
⊢ (𝑥 = ∅ →
(♯‘𝑥) =
(♯‘∅)) | 
| 4 | 3 | oveq2d 7447 | . . . . 5
⊢ (𝑥 = ∅ →
((♯‘𝐴)↑(♯‘𝑥)) = ((♯‘𝐴)↑(♯‘∅))) | 
| 5 | 2, 4 | eqeq12d 2753 | . . . 4
⊢ (𝑥 = ∅ →
((♯‘(𝐴
↑m 𝑥)) =
((♯‘𝐴)↑(♯‘𝑥)) ↔ (♯‘(𝐴 ↑m ∅)) =
((♯‘𝐴)↑(♯‘∅)))) | 
| 6 | 5 | imbi2d 340 | . . 3
⊢ (𝑥 = ∅ → ((𝐴 ∈ Fin →
(♯‘(𝐴
↑m 𝑥)) =
((♯‘𝐴)↑(♯‘𝑥))) ↔ (𝐴 ∈ Fin → (♯‘(𝐴 ↑m ∅)) =
((♯‘𝐴)↑(♯‘∅))))) | 
| 7 |  | oveq2 7439 | . . . . . 6
⊢ (𝑥 = 𝑦 → (𝐴 ↑m 𝑥) = (𝐴 ↑m 𝑦)) | 
| 8 | 7 | fveq2d 6910 | . . . . 5
⊢ (𝑥 = 𝑦 → (♯‘(𝐴 ↑m 𝑥)) = (♯‘(𝐴 ↑m 𝑦))) | 
| 9 |  | fveq2 6906 | . . . . . 6
⊢ (𝑥 = 𝑦 → (♯‘𝑥) = (♯‘𝑦)) | 
| 10 | 9 | oveq2d 7447 | . . . . 5
⊢ (𝑥 = 𝑦 → ((♯‘𝐴)↑(♯‘𝑥)) = ((♯‘𝐴)↑(♯‘𝑦))) | 
| 11 | 8, 10 | eqeq12d 2753 | . . . 4
⊢ (𝑥 = 𝑦 → ((♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥)) ↔ (♯‘(𝐴 ↑m 𝑦)) = ((♯‘𝐴)↑(♯‘𝑦)))) | 
| 12 | 11 | imbi2d 340 | . . 3
⊢ (𝑥 = 𝑦 → ((𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥))) ↔ (𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝑦)) = ((♯‘𝐴)↑(♯‘𝑦))))) | 
| 13 |  | oveq2 7439 | . . . . . 6
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → (𝐴 ↑m 𝑥) = (𝐴 ↑m (𝑦 ∪ {𝑧}))) | 
| 14 | 13 | fveq2d 6910 | . . . . 5
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → (♯‘(𝐴 ↑m 𝑥)) = (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧})))) | 
| 15 |  | fveq2 6906 | . . . . . 6
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → (♯‘𝑥) = (♯‘(𝑦 ∪ {𝑧}))) | 
| 16 | 15 | oveq2d 7447 | . . . . 5
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → ((♯‘𝐴)↑(♯‘𝑥)) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧})))) | 
| 17 | 14, 16 | eqeq12d 2753 | . . . 4
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → ((♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥)) ↔ (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧}))))) | 
| 18 | 17 | imbi2d 340 | . . 3
⊢ (𝑥 = (𝑦 ∪ {𝑧}) → ((𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥))) ↔ (𝐴 ∈ Fin → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧})))))) | 
| 19 |  | oveq2 7439 | . . . . . 6
⊢ (𝑥 = 𝐵 → (𝐴 ↑m 𝑥) = (𝐴 ↑m 𝐵)) | 
| 20 | 19 | fveq2d 6910 | . . . . 5
⊢ (𝑥 = 𝐵 → (♯‘(𝐴 ↑m 𝑥)) = (♯‘(𝐴 ↑m 𝐵))) | 
| 21 |  | fveq2 6906 | . . . . . 6
⊢ (𝑥 = 𝐵 → (♯‘𝑥) = (♯‘𝐵)) | 
| 22 | 21 | oveq2d 7447 | . . . . 5
⊢ (𝑥 = 𝐵 → ((♯‘𝐴)↑(♯‘𝑥)) = ((♯‘𝐴)↑(♯‘𝐵))) | 
| 23 | 20, 22 | eqeq12d 2753 | . . . 4
⊢ (𝑥 = 𝐵 → ((♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥)) ↔ (♯‘(𝐴 ↑m 𝐵)) = ((♯‘𝐴)↑(♯‘𝐵)))) | 
| 24 | 23 | imbi2d 340 | . . 3
⊢ (𝑥 = 𝐵 → ((𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝑥)) = ((♯‘𝐴)↑(♯‘𝑥))) ↔ (𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝐵)) = ((♯‘𝐴)↑(♯‘𝐵))))) | 
| 25 |  | hashcl 14395 | . . . . . 6
⊢ (𝐴 ∈ Fin →
(♯‘𝐴) ∈
ℕ0) | 
| 26 | 25 | nn0cnd 12589 | . . . . 5
⊢ (𝐴 ∈ Fin →
(♯‘𝐴) ∈
ℂ) | 
| 27 | 26 | exp0d 14180 | . . . 4
⊢ (𝐴 ∈ Fin →
((♯‘𝐴)↑0)
= 1) | 
| 28 |  | hash0 14406 | . . . . . 6
⊢
(♯‘∅) = 0 | 
| 29 | 28 | oveq2i 7442 | . . . . 5
⊢
((♯‘𝐴)↑(♯‘∅)) =
((♯‘𝐴)↑0) | 
| 30 | 29 | a1i 11 | . . . 4
⊢ (𝐴 ∈ Fin →
((♯‘𝐴)↑(♯‘∅)) =
((♯‘𝐴)↑0)) | 
| 31 |  | mapdm0 8882 | . . . . . 6
⊢ (𝐴 ∈ Fin → (𝐴 ↑m ∅) =
{∅}) | 
| 32 | 31 | fveq2d 6910 | . . . . 5
⊢ (𝐴 ∈ Fin →
(♯‘(𝐴
↑m ∅)) = (♯‘{∅})) | 
| 33 |  | 0ex 5307 | . . . . . 6
⊢ ∅
∈ V | 
| 34 |  | hashsng 14408 | . . . . . 6
⊢ (∅
∈ V → (♯‘{∅}) = 1) | 
| 35 | 33, 34 | mp1i 13 | . . . . 5
⊢ (𝐴 ∈ Fin →
(♯‘{∅}) = 1) | 
| 36 | 32, 35 | eqtrd 2777 | . . . 4
⊢ (𝐴 ∈ Fin →
(♯‘(𝐴
↑m ∅)) = 1) | 
| 37 | 27, 30, 36 | 3eqtr4rd 2788 | . . 3
⊢ (𝐴 ∈ Fin →
(♯‘(𝐴
↑m ∅)) = ((♯‘𝐴)↑(♯‘∅))) | 
| 38 |  | oveq1 7438 | . . . . . 6
⊢
((♯‘(𝐴
↑m 𝑦)) =
((♯‘𝐴)↑(♯‘𝑦)) → ((♯‘(𝐴 ↑m 𝑦)) · (♯‘𝐴)) = (((♯‘𝐴)↑(♯‘𝑦)) · (♯‘𝐴))) | 
| 39 |  | vex 3484 | . . . . . . . . . . 11
⊢ 𝑦 ∈ V | 
| 40 | 39 | a1i 11 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → 𝑦 ∈ V) | 
| 41 |  | vsnex 5434 | . . . . . . . . . . 11
⊢ {𝑧} ∈ V | 
| 42 | 41 | a1i 11 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → {𝑧} ∈ V) | 
| 43 |  | elex 3501 | . . . . . . . . . . 11
⊢ (𝐴 ∈ Fin → 𝐴 ∈ V) | 
| 44 | 43 | adantr 480 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → 𝐴 ∈ V) | 
| 45 |  | simprr 773 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ¬ 𝑧 ∈ 𝑦) | 
| 46 |  | disjsn 4711 | . . . . . . . . . . 11
⊢ ((𝑦 ∩ {𝑧}) = ∅ ↔ ¬ 𝑧 ∈ 𝑦) | 
| 47 | 45, 46 | sylibr 234 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝑦 ∩ {𝑧}) = ∅) | 
| 48 |  | mapunen 9186 | . . . . . . . . . 10
⊢ (((𝑦 ∈ V ∧ {𝑧} ∈ V ∧ 𝐴 ∈ V) ∧ (𝑦 ∩ {𝑧}) = ∅) → (𝐴 ↑m (𝑦 ∪ {𝑧})) ≈ ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧}))) | 
| 49 | 40, 42, 44, 47, 48 | syl31anc 1375 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝐴 ↑m (𝑦 ∪ {𝑧})) ≈ ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧}))) | 
| 50 |  | simpl 482 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → 𝐴 ∈ Fin) | 
| 51 |  | simprl 771 | . . . . . . . . . . . 12
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → 𝑦 ∈ Fin) | 
| 52 |  | snfi 9083 | . . . . . . . . . . . 12
⊢ {𝑧} ∈ Fin | 
| 53 |  | unfi 9211 | . . . . . . . . . . . 12
⊢ ((𝑦 ∈ Fin ∧ {𝑧} ∈ Fin) → (𝑦 ∪ {𝑧}) ∈ Fin) | 
| 54 | 51, 52, 53 | sylancl 586 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝑦 ∪ {𝑧}) ∈ Fin) | 
| 55 |  | mapfi 9388 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∪ {𝑧}) ∈ Fin) → (𝐴 ↑m (𝑦 ∪ {𝑧})) ∈ Fin) | 
| 56 | 50, 54, 55 | syl2anc 584 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝐴 ↑m (𝑦 ∪ {𝑧})) ∈ Fin) | 
| 57 |  | mapfi 9388 | . . . . . . . . . . . 12
⊢ ((𝐴 ∈ Fin ∧ 𝑦 ∈ Fin) → (𝐴 ↑m 𝑦) ∈ Fin) | 
| 58 | 57 | adantrr 717 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝐴 ↑m 𝑦) ∈ Fin) | 
| 59 |  | mapfi 9388 | . . . . . . . . . . . 12
⊢ ((𝐴 ∈ Fin ∧ {𝑧} ∈ Fin) → (𝐴 ↑m {𝑧}) ∈ Fin) | 
| 60 | 50, 52, 59 | sylancl 586 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝐴 ↑m {𝑧}) ∈ Fin) | 
| 61 |  | xpfi 9358 | . . . . . . . . . . 11
⊢ (((𝐴 ↑m 𝑦) ∈ Fin ∧ (𝐴 ↑m {𝑧}) ∈ Fin) → ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})) ∈ Fin) | 
| 62 | 58, 60, 61 | syl2anc 584 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})) ∈ Fin) | 
| 63 |  | hashen 14386 | . . . . . . . . . 10
⊢ (((𝐴 ↑m (𝑦 ∪ {𝑧})) ∈ Fin ∧ ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})) ∈ Fin) → ((♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = (♯‘((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧}))) ↔ (𝐴 ↑m (𝑦 ∪ {𝑧})) ≈ ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})))) | 
| 64 | 56, 62, 63 | syl2anc 584 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = (♯‘((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧}))) ↔ (𝐴 ↑m (𝑦 ∪ {𝑧})) ≈ ((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})))) | 
| 65 | 49, 64 | mpbird 257 | . . . . . . . 8
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = (♯‘((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧})))) | 
| 66 |  | hashxp 14473 | . . . . . . . . 9
⊢ (((𝐴 ↑m 𝑦) ∈ Fin ∧ (𝐴 ↑m {𝑧}) ∈ Fin) →
(♯‘((𝐴
↑m 𝑦)
× (𝐴
↑m {𝑧}))) =
((♯‘(𝐴
↑m 𝑦))
· (♯‘(𝐴
↑m {𝑧})))) | 
| 67 | 58, 60, 66 | syl2anc 584 | . . . . . . . 8
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘((𝐴 ↑m 𝑦) × (𝐴 ↑m {𝑧}))) = ((♯‘(𝐴 ↑m 𝑦)) · (♯‘(𝐴 ↑m {𝑧})))) | 
| 68 |  | vex 3484 | . . . . . . . . . . . 12
⊢ 𝑧 ∈ V | 
| 69 | 68 | a1i 11 | . . . . . . . . . . 11
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → 𝑧 ∈ V) | 
| 70 | 50, 69 | mapsnend 9076 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (𝐴 ↑m {𝑧}) ≈ 𝐴) | 
| 71 |  | hashen 14386 | . . . . . . . . . . 11
⊢ (((𝐴 ↑m {𝑧}) ∈ Fin ∧ 𝐴 ∈ Fin) →
((♯‘(𝐴
↑m {𝑧})) =
(♯‘𝐴) ↔
(𝐴 ↑m
{𝑧}) ≈ 𝐴)) | 
| 72 | 60, 50, 71 | syl2anc 584 | . . . . . . . . . 10
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘(𝐴 ↑m {𝑧})) = (♯‘𝐴) ↔ (𝐴 ↑m {𝑧}) ≈ 𝐴)) | 
| 73 | 70, 72 | mpbird 257 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘(𝐴 ↑m {𝑧})) = (♯‘𝐴)) | 
| 74 | 73 | oveq2d 7447 | . . . . . . . 8
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘(𝐴 ↑m 𝑦)) · (♯‘(𝐴 ↑m {𝑧}))) = ((♯‘(𝐴 ↑m 𝑦)) · (♯‘𝐴))) | 
| 75 | 65, 67, 74 | 3eqtrd 2781 | . . . . . . 7
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘(𝐴 ↑m 𝑦)) · (♯‘𝐴))) | 
| 76 |  | hashunsng 14431 | . . . . . . . . . . 11
⊢ (𝑧 ∈ V → ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → (♯‘(𝑦 ∪ {𝑧})) = ((♯‘𝑦) + 1))) | 
| 77 | 76 | elv 3485 | . . . . . . . . . 10
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → (♯‘(𝑦 ∪ {𝑧})) = ((♯‘𝑦) + 1)) | 
| 78 | 77 | adantl 481 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘(𝑦 ∪ {𝑧})) = ((♯‘𝑦) + 1)) | 
| 79 | 78 | oveq2d 7447 | . . . . . . . 8
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑((♯‘𝑦) + 1))) | 
| 80 | 26 | adantr 480 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘𝐴) ∈ ℂ) | 
| 81 |  | hashcl 14395 | . . . . . . . . . 10
⊢ (𝑦 ∈ Fin →
(♯‘𝑦) ∈
ℕ0) | 
| 82 | 81 | ad2antrl 728 | . . . . . . . . 9
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → (♯‘𝑦) ∈
ℕ0) | 
| 83 | 80, 82 | expp1d 14187 | . . . . . . . 8
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘𝐴)↑((♯‘𝑦) + 1)) = (((♯‘𝐴)↑(♯‘𝑦)) · (♯‘𝐴))) | 
| 84 | 79, 83 | eqtrd 2777 | . . . . . . 7
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧}))) = (((♯‘𝐴)↑(♯‘𝑦)) · (♯‘𝐴))) | 
| 85 | 75, 84 | eqeq12d 2753 | . . . . . 6
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧}))) ↔ ((♯‘(𝐴 ↑m 𝑦)) · (♯‘𝐴)) = (((♯‘𝐴)↑(♯‘𝑦)) · (♯‘𝐴)))) | 
| 86 | 38, 85 | imbitrrid 246 | . . . . 5
⊢ ((𝐴 ∈ Fin ∧ (𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦)) → ((♯‘(𝐴 ↑m 𝑦)) = ((♯‘𝐴)↑(♯‘𝑦)) → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧}))))) | 
| 87 | 86 | expcom 413 | . . . 4
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → (𝐴 ∈ Fin → ((♯‘(𝐴 ↑m 𝑦)) = ((♯‘𝐴)↑(♯‘𝑦)) → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧})))))) | 
| 88 | 87 | a2d 29 | . . 3
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → ((𝐴 ∈ Fin → (♯‘(𝐴 ↑m 𝑦)) = ((♯‘𝐴)↑(♯‘𝑦))) → (𝐴 ∈ Fin → (♯‘(𝐴 ↑m (𝑦 ∪ {𝑧}))) = ((♯‘𝐴)↑(♯‘(𝑦 ∪ {𝑧})))))) | 
| 89 | 6, 12, 18, 24, 37, 88 | findcard2s 9205 | . 2
⊢ (𝐵 ∈ Fin → (𝐴 ∈ Fin →
(♯‘(𝐴
↑m 𝐵)) =
((♯‘𝐴)↑(♯‘𝐵)))) | 
| 90 | 89 | impcom 407 | 1
⊢ ((𝐴 ∈ Fin ∧ 𝐵 ∈ Fin) →
(♯‘(𝐴
↑m 𝐵)) =
((♯‘𝐴)↑(♯‘𝐵))) |