| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | ssid 4006 | . 2
⊢ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} | 
| 2 |  | hashf1lem2.2 | . . . . 5
⊢ (𝜑 → 𝐵 ∈ Fin) | 
| 3 |  | hashf1lem2.1 | . . . . 5
⊢ (𝜑 → 𝐴 ∈ Fin) | 
| 4 |  | mapfi 9388 | . . . . 5
⊢ ((𝐵 ∈ Fin ∧ 𝐴 ∈ Fin) → (𝐵 ↑m 𝐴) ∈ Fin) | 
| 5 | 2, 3, 4 | syl2anc 584 | . . . 4
⊢ (𝜑 → (𝐵 ↑m 𝐴) ∈ Fin) | 
| 6 |  | f1f 6804 | . . . . . 6
⊢ (𝑓:𝐴–1-1→𝐵 → 𝑓:𝐴⟶𝐵) | 
| 7 | 2, 3 | elmapd 8880 | . . . . . 6
⊢ (𝜑 → (𝑓 ∈ (𝐵 ↑m 𝐴) ↔ 𝑓:𝐴⟶𝐵)) | 
| 8 | 6, 7 | imbitrrid 246 | . . . . 5
⊢ (𝜑 → (𝑓:𝐴–1-1→𝐵 → 𝑓 ∈ (𝐵 ↑m 𝐴))) | 
| 9 | 8 | abssdv 4068 | . . . 4
⊢ (𝜑 → {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ (𝐵 ↑m 𝐴)) | 
| 10 | 5, 9 | ssfid 9301 | . . 3
⊢ (𝜑 → {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ∈ Fin) | 
| 11 |  | sseq1 4009 | . . . . . 6
⊢ (𝑥 = ∅ → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ ∅ ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) | 
| 12 |  | eleq2 2830 | . . . . . . . . . . . . 13
⊢ (𝑥 = ∅ → ((𝑓 ↾ 𝐴) ∈ 𝑥 ↔ (𝑓 ↾ 𝐴) ∈ ∅)) | 
| 13 |  | noel 4338 | . . . . . . . . . . . . . 14
⊢  ¬
(𝑓 ↾ 𝐴) ∈
∅ | 
| 14 | 13 | pm2.21i 119 | . . . . . . . . . . . . 13
⊢ ((𝑓 ↾ 𝐴) ∈ ∅ → 𝑓 ∈ ∅) | 
| 15 | 12, 14 | biimtrdi 253 | . . . . . . . . . . . 12
⊢ (𝑥 = ∅ → ((𝑓 ↾ 𝐴) ∈ 𝑥 → 𝑓 ∈ ∅)) | 
| 16 | 15 | adantrd 491 | . . . . . . . . . . 11
⊢ (𝑥 = ∅ → (((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) → 𝑓 ∈ ∅)) | 
| 17 | 16 | abssdv 4068 | . . . . . . . . . 10
⊢ (𝑥 = ∅ → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ ∅) | 
| 18 |  | ss0 4402 | . . . . . . . . . 10
⊢ ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ ∅ → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = ∅) | 
| 19 | 17, 18 | syl 17 | . . . . . . . . 9
⊢ (𝑥 = ∅ → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = ∅) | 
| 20 | 19 | fveq2d 6910 | . . . . . . . 8
⊢ (𝑥 = ∅ →
(♯‘{𝑓 ∣
((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) =
(♯‘∅)) | 
| 21 |  | hash0 14406 | . . . . . . . 8
⊢
(♯‘∅) = 0 | 
| 22 | 20, 21 | eqtrdi 2793 | . . . . . . 7
⊢ (𝑥 = ∅ →
(♯‘{𝑓 ∣
((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = 0) | 
| 23 |  | fveq2 6906 | . . . . . . . . 9
⊢ (𝑥 = ∅ →
(♯‘𝑥) =
(♯‘∅)) | 
| 24 | 23, 21 | eqtrdi 2793 | . . . . . . . 8
⊢ (𝑥 = ∅ →
(♯‘𝑥) =
0) | 
| 25 | 24 | oveq2d 7447 | . . . . . . 7
⊢ (𝑥 = ∅ →
(((♯‘𝐵) −
(♯‘𝐴)) ·
(♯‘𝑥)) =
(((♯‘𝐵) −
(♯‘𝐴)) ·
0)) | 
| 26 | 22, 25 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = ∅ →
((♯‘{𝑓 ∣
((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) ↔ 0 =
(((♯‘𝐵) −
(♯‘𝐴)) ·
0))) | 
| 27 | 11, 26 | imbi12d 344 | . . . . 5
⊢ (𝑥 = ∅ → ((𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥))) ↔ (∅ ⊆
{𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → 0 = (((♯‘𝐵) − (♯‘𝐴)) ·
0)))) | 
| 28 | 27 | imbi2d 340 | . . . 4
⊢ (𝑥 = ∅ → ((𝜑 → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)))) ↔ (𝜑 → (∅ ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → 0 = (((♯‘𝐵) − (♯‘𝐴)) ·
0))))) | 
| 29 |  | sseq1 4009 | . . . . . 6
⊢ (𝑥 = 𝑦 → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ 𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) | 
| 30 |  | eleq2 2830 | . . . . . . . . . 10
⊢ (𝑥 = 𝑦 → ((𝑓 ↾ 𝐴) ∈ 𝑥 ↔ (𝑓 ↾ 𝐴) ∈ 𝑦)) | 
| 31 | 30 | anbi1d 631 | . . . . . . . . 9
⊢ (𝑥 = 𝑦 → (((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 32 | 31 | abbidv 2808 | . . . . . . . 8
⊢ (𝑥 = 𝑦 → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) | 
| 33 | 32 | fveq2d 6910 | . . . . . . 7
⊢ (𝑥 = 𝑦 → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) | 
| 34 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑥 = 𝑦 → (♯‘𝑥) = (♯‘𝑦)) | 
| 35 | 34 | oveq2d 7447 | . . . . . . 7
⊢ (𝑥 = 𝑦 → (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))) | 
| 36 | 33, 35 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = 𝑦 → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) ↔ (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)))) | 
| 37 | 29, 36 | imbi12d 344 | . . . . 5
⊢ (𝑥 = 𝑦 → ((𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥))) ↔ (𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))))) | 
| 38 | 37 | imbi2d 340 | . . . 4
⊢ (𝑥 = 𝑦 → ((𝜑 → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)))) ↔ (𝜑 → (𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)))))) | 
| 39 |  | sseq1 4009 | . . . . . 6
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) | 
| 40 |  | eleq2 2830 | . . . . . . . . . 10
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → ((𝑓 ↾ 𝐴) ∈ 𝑥 ↔ (𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}))) | 
| 41 | 40 | anbi1d 631 | . . . . . . . . 9
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → (((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 42 | 41 | abbidv 2808 | . . . . . . . 8
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) | 
| 43 | 42 | fveq2d 6910 | . . . . . . 7
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) | 
| 44 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → (♯‘𝑥) = (♯‘(𝑦 ∪ {𝑎}))) | 
| 45 | 44 | oveq2d 7447 | . . . . . . 7
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) = (((♯‘𝐵) − (♯‘𝐴)) ·
(♯‘(𝑦 ∪
{𝑎})))) | 
| 46 | 43, 45 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) ↔ (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))))) | 
| 47 | 39, 46 | imbi12d 344 | . . . . 5
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → ((𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥))) ↔ ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎})))))) | 
| 48 | 47 | imbi2d 340 | . . . 4
⊢ (𝑥 = (𝑦 ∪ {𝑎}) → ((𝜑 → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)))) ↔ (𝜑 → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))))))) | 
| 49 |  | sseq1 4009 | . . . . . 6
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) | 
| 50 |  | f1eq1 6799 | . . . . . . . . . . 11
⊢ (𝑓 = 𝑦 → (𝑓:𝐴–1-1→𝐵 ↔ 𝑦:𝐴–1-1→𝐵)) | 
| 51 | 50 | cbvabv 2812 | . . . . . . . . . 10
⊢ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} | 
| 52 | 51 | eqeq2i 2750 | . . . . . . . . 9
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ 𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵}) | 
| 53 |  | ssun1 4178 | . . . . . . . . . . . . . . 15
⊢ 𝐴 ⊆ (𝐴 ∪ {𝑧}) | 
| 54 |  | f1ssres 6811 | . . . . . . . . . . . . . . 15
⊢ ((𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 ∧ 𝐴 ⊆ (𝐴 ∪ {𝑧})) → (𝑓 ↾ 𝐴):𝐴–1-1→𝐵) | 
| 55 | 53, 54 | mpan2 691 | . . . . . . . . . . . . . 14
⊢ (𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 → (𝑓 ↾ 𝐴):𝐴–1-1→𝐵) | 
| 56 |  | vex 3484 | . . . . . . . . . . . . . . . 16
⊢ 𝑓 ∈ V | 
| 57 | 56 | resex 6047 | . . . . . . . . . . . . . . 15
⊢ (𝑓 ↾ 𝐴) ∈ V | 
| 58 |  | f1eq1 6799 | . . . . . . . . . . . . . . 15
⊢ (𝑦 = (𝑓 ↾ 𝐴) → (𝑦:𝐴–1-1→𝐵 ↔ (𝑓 ↾ 𝐴):𝐴–1-1→𝐵)) | 
| 59 | 57, 58 | elab 3679 | . . . . . . . . . . . . . 14
⊢ ((𝑓 ↾ 𝐴) ∈ {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} ↔ (𝑓 ↾ 𝐴):𝐴–1-1→𝐵) | 
| 60 | 55, 59 | sylibr 234 | . . . . . . . . . . . . 13
⊢ (𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 → (𝑓 ↾ 𝐴) ∈ {𝑦 ∣ 𝑦:𝐴–1-1→𝐵}) | 
| 61 |  | eleq2 2830 | . . . . . . . . . . . . 13
⊢ (𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} → ((𝑓 ↾ 𝐴) ∈ 𝑥 ↔ (𝑓 ↾ 𝐴) ∈ {𝑦 ∣ 𝑦:𝐴–1-1→𝐵})) | 
| 62 | 60, 61 | imbitrrid 246 | . . . . . . . . . . . 12
⊢ (𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} → (𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 → (𝑓 ↾ 𝐴) ∈ 𝑥)) | 
| 63 | 62 | pm4.71rd 562 | . . . . . . . . . . 11
⊢ (𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} → (𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 ↔ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 64 | 63 | bicomd 223 | . . . . . . . . . 10
⊢ (𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} → (((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) | 
| 65 | 64 | abbidv 2808 | . . . . . . . . 9
⊢ (𝑥 = {𝑦 ∣ 𝑦:𝐴–1-1→𝐵} → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) | 
| 66 | 52, 65 | sylbi 217 | . . . . . . . 8
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) | 
| 67 | 66 | fveq2d 6910 | . . . . . . 7
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵})) | 
| 68 |  | fveq2 6906 | . . . . . . . 8
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘𝑥) = (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) | 
| 69 | 68 | oveq2d 7447 | . . . . . . 7
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) = (((♯‘𝐵) − (♯‘𝐴)) ·
(♯‘{𝑓 ∣
𝑓:𝐴–1-1→𝐵}))) | 
| 70 | 67, 69 | eqeq12d 2753 | . . . . . 6
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)) ↔ (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵})))) | 
| 71 | 49, 70 | imbi12d 344 | . . . . 5
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → ((𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥))) ↔ ({𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵}))))) | 
| 72 | 71 | imbi2d 340 | . . . 4
⊢ (𝑥 = {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → ((𝜑 → (𝑥 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑥 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑥)))) ↔ (𝜑 → ({𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵})))))) | 
| 73 |  | hashcl 14395 | . . . . . . . . . 10
⊢ (𝐵 ∈ Fin →
(♯‘𝐵) ∈
ℕ0) | 
| 74 | 2, 73 | syl 17 | . . . . . . . . 9
⊢ (𝜑 → (♯‘𝐵) ∈
ℕ0) | 
| 75 | 74 | nn0cnd 12589 | . . . . . . . 8
⊢ (𝜑 → (♯‘𝐵) ∈
ℂ) | 
| 76 |  | hashcl 14395 | . . . . . . . . . 10
⊢ (𝐴 ∈ Fin →
(♯‘𝐴) ∈
ℕ0) | 
| 77 | 3, 76 | syl 17 | . . . . . . . . 9
⊢ (𝜑 → (♯‘𝐴) ∈
ℕ0) | 
| 78 | 77 | nn0cnd 12589 | . . . . . . . 8
⊢ (𝜑 → (♯‘𝐴) ∈
ℂ) | 
| 79 | 75, 78 | subcld 11620 | . . . . . . 7
⊢ (𝜑 → ((♯‘𝐵) − (♯‘𝐴)) ∈
ℂ) | 
| 80 | 79 | mul01d 11460 | . . . . . 6
⊢ (𝜑 → (((♯‘𝐵) − (♯‘𝐴)) · 0) =
0) | 
| 81 | 80 | eqcomd 2743 | . . . . 5
⊢ (𝜑 → 0 = (((♯‘𝐵) − (♯‘𝐴)) · 0)) | 
| 82 | 81 | a1d 25 | . . . 4
⊢ (𝜑 → (∅ ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → 0 = (((♯‘𝐵) − (♯‘𝐴)) ·
0))) | 
| 83 |  | ssun1 4178 | . . . . . . . . 9
⊢ 𝑦 ⊆ (𝑦 ∪ {𝑎}) | 
| 84 |  | sstr 3992 | . . . . . . . . 9
⊢ ((𝑦 ⊆ (𝑦 ∪ {𝑎}) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) → 𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 85 | 83, 84 | mpan 690 | . . . . . . . 8
⊢ ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → 𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 86 | 85 | imim1i 63 | . . . . . . 7
⊢ ((𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))) → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)))) | 
| 87 |  | oveq1 7438 | . . . . . . . . . 10
⊢
((♯‘{𝑓
∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + ((♯‘𝐵) − (♯‘𝐴))) = ((((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) + ((♯‘𝐵) − (♯‘𝐴)))) | 
| 88 |  | elun 4153 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ↔ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) ∈ {𝑎})) | 
| 89 | 57 | elsn 4641 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝑓 ↾ 𝐴) ∈ {𝑎} ↔ (𝑓 ↾ 𝐴) = 𝑎) | 
| 90 | 89 | orbi2i 913 | . . . . . . . . . . . . . . . . . . 19
⊢ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) ∈ {𝑎}) ↔ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) = 𝑎)) | 
| 91 | 88, 90 | bitri 275 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ↔ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) = 𝑎)) | 
| 92 | 91 | anbi1i 624 | . . . . . . . . . . . . . . . . 17
⊢ (((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) = 𝑎) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) | 
| 93 |  | andir 1011 | . . . . . . . . . . . . . . . . 17
⊢ ((((𝑓 ↾ 𝐴) ∈ 𝑦 ∨ (𝑓 ↾ 𝐴) = 𝑎) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∨ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 94 | 92, 93 | bitri 275 | . . . . . . . . . . . . . . . 16
⊢ (((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ↔ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∨ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 95 | 94 | abbii 2809 | . . . . . . . . . . . . . . 15
⊢ {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = {𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∨ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} | 
| 96 |  | unab 4308 | . . . . . . . . . . . . . . 15
⊢ ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∪ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = {𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∨ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} | 
| 97 | 95, 96 | eqtr4i 2768 | . . . . . . . . . . . . . 14
⊢ {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} = ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∪ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) | 
| 98 | 97 | fveq2i 6909 | . . . . . . . . . . . . 13
⊢
(♯‘{𝑓
∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∪ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) | 
| 99 |  | snfi 9083 | . . . . . . . . . . . . . . . . . . 19
⊢ {𝑧} ∈ Fin | 
| 100 |  | unfi 9211 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝐴 ∈ Fin ∧ {𝑧} ∈ Fin) → (𝐴 ∪ {𝑧}) ∈ Fin) | 
| 101 | 3, 99, 100 | sylancl 586 | . . . . . . . . . . . . . . . . . 18
⊢ (𝜑 → (𝐴 ∪ {𝑧}) ∈ Fin) | 
| 102 |  | mapvalg 8876 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝐵 ∈ Fin ∧ (𝐴 ∪ {𝑧}) ∈ Fin) → (𝐵 ↑m (𝐴 ∪ {𝑧})) = {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵}) | 
| 103 | 2, 101, 102 | syl2anc 584 | . . . . . . . . . . . . . . . . 17
⊢ (𝜑 → (𝐵 ↑m (𝐴 ∪ {𝑧})) = {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵}) | 
| 104 |  | mapfi 9388 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝐵 ∈ Fin ∧ (𝐴 ∪ {𝑧}) ∈ Fin) → (𝐵 ↑m (𝐴 ∪ {𝑧})) ∈ Fin) | 
| 105 | 2, 101, 104 | syl2anc 584 | . . . . . . . . . . . . . . . . 17
⊢ (𝜑 → (𝐵 ↑m (𝐴 ∪ {𝑧})) ∈ Fin) | 
| 106 | 103, 105 | eqeltrrd 2842 | . . . . . . . . . . . . . . . 16
⊢ (𝜑 → {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵} ∈ Fin) | 
| 107 |  | f1f 6804 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵 → 𝑓:(𝐴 ∪ {𝑧})⟶𝐵) | 
| 108 | 107 | adantl 481 | . . . . . . . . . . . . . . . . 17
⊢ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) → 𝑓:(𝐴 ∪ {𝑧})⟶𝐵) | 
| 109 | 108 | ss2abi 4067 | . . . . . . . . . . . . . . . 16
⊢ {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵} | 
| 110 |  | ssfi 9213 | . . . . . . . . . . . . . . . 16
⊢ (({𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵} ∈ Fin ∧ {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵}) → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 111 | 106, 109,
110 | sylancl 586 | . . . . . . . . . . . . . . 15
⊢ (𝜑 → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 112 | 111 | adantr 480 | . . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → {𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 113 | 107 | adantl 481 | . . . . . . . . . . . . . . . . 17
⊢ (((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) → 𝑓:(𝐴 ∪ {𝑧})⟶𝐵) | 
| 114 | 113 | ss2abi 4067 | . . . . . . . . . . . . . . . 16
⊢ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵} | 
| 115 |  | ssfi 9213 | . . . . . . . . . . . . . . . 16
⊢ (({𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵} ∈ Fin ∧ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ⊆ {𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})⟶𝐵}) → {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 116 | 106, 114,
115 | sylancl 586 | . . . . . . . . . . . . . . 15
⊢ (𝜑 → {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 117 | 116 | adantr 480 | . . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 118 |  | inab 4309 | . . . . . . . . . . . . . . 15
⊢ ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∩ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = {𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} | 
| 119 |  | simprlr 780 | . . . . . . . . . . . . . . . 16
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ¬ 𝑎 ∈ 𝑦) | 
| 120 |  | abn0 4385 | . . . . . . . . . . . . . . . . . 18
⊢ ({𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} ≠ ∅ ↔ ∃𝑓(((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))) | 
| 121 |  | simprl 771 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) → (𝑓 ↾ 𝐴) = 𝑎) | 
| 122 |  | simpll 767 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) → (𝑓 ↾ 𝐴) ∈ 𝑦) | 
| 123 | 121, 122 | eqeltrrd 2842 | . . . . . . . . . . . . . . . . . . 19
⊢ ((((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) → 𝑎 ∈ 𝑦) | 
| 124 | 123 | exlimiv 1930 | . . . . . . . . . . . . . . . . . 18
⊢
(∃𝑓(((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)) → 𝑎 ∈ 𝑦) | 
| 125 | 120, 124 | sylbi 217 | . . . . . . . . . . . . . . . . 17
⊢ ({𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} ≠ ∅ → 𝑎 ∈ 𝑦) | 
| 126 | 125 | necon1bi 2969 | . . . . . . . . . . . . . . . 16
⊢ (¬
𝑎 ∈ 𝑦 → {𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} = ∅) | 
| 127 | 119, 126 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → {𝑓 ∣ (((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵) ∧ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵))} = ∅) | 
| 128 | 118, 127 | eqtrid 2789 | . . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∩ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ∅) | 
| 129 |  | hashun 14421 | . . . . . . . . . . . . . 14
⊢ (({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin ∧ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin ∧ ({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∩ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ∅) → (♯‘({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∪ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) = ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}))) | 
| 130 | 112, 117,
128, 129 | syl3anc 1373 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘({𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∪ {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) = ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}))) | 
| 131 | 98, 130 | eqtrid 2789 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}))) | 
| 132 |  | simpr 484 | . . . . . . . . . . . . . . . . 17
⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) → (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 133 | 132 | unssbd 4194 | . . . . . . . . . . . . . . . 16
⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) → {𝑎} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 134 |  | vex 3484 | . . . . . . . . . . . . . . . . 17
⊢ 𝑎 ∈ V | 
| 135 | 134 | snss 4785 | . . . . . . . . . . . . . . . 16
⊢ (𝑎 ∈ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ {𝑎} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 136 | 133, 135 | sylibr 234 | . . . . . . . . . . . . . . 15
⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) → 𝑎 ∈ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) | 
| 137 |  | f1eq1 6799 | . . . . . . . . . . . . . . . 16
⊢ (𝑓 = 𝑎 → (𝑓:𝐴–1-1→𝐵 ↔ 𝑎:𝐴–1-1→𝐵)) | 
| 138 | 134, 137 | elab 3679 | . . . . . . . . . . . . . . 15
⊢ (𝑎 ∈ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ↔ 𝑎:𝐴–1-1→𝐵) | 
| 139 | 136, 138 | sylib 218 | . . . . . . . . . . . . . 14
⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵}) → 𝑎:𝐴–1-1→𝐵) | 
| 140 | 78 | adantr 480 | . . . . . . . . . . . . . . . 16
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘𝐴) ∈ ℂ) | 
| 141 | 116 | adantr 480 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin) | 
| 142 |  | hashcl 14395 | . . . . . . . . . . . . . . . . . 18
⊢ ({𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ∈ Fin → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) ∈
ℕ0) | 
| 143 | 141, 142 | syl 17 | . . . . . . . . . . . . . . . . 17
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) ∈
ℕ0) | 
| 144 | 143 | nn0cnd 12589 | . . . . . . . . . . . . . . . 16
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) ∈ ℂ) | 
| 145 | 140, 144 | pncan2d 11622 | . . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (((♯‘𝐴) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) − (♯‘𝐴)) = (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) | 
| 146 |  | f1f1orn 6859 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑎:𝐴–1-1→𝐵 → 𝑎:𝐴–1-1-onto→ran
𝑎) | 
| 147 | 146 | adantl 481 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → 𝑎:𝐴–1-1-onto→ran
𝑎) | 
| 148 |  | f1oen3g 9007 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝑎 ∈ V ∧ 𝑎:𝐴–1-1-onto→ran
𝑎) → 𝐴 ≈ ran 𝑎) | 
| 149 | 134, 147,
148 | sylancr 587 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → 𝐴 ≈ ran 𝑎) | 
| 150 |  | hasheni 14387 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝐴 ≈ ran 𝑎 → (♯‘𝐴) = (♯‘ran 𝑎)) | 
| 151 | 149, 150 | syl 17 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘𝐴) = (♯‘ran 𝑎)) | 
| 152 | 3 | adantr 480 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → 𝐴 ∈ Fin) | 
| 153 | 2 | adantr 480 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → 𝐵 ∈ Fin) | 
| 154 |  | hashf1lem2.3 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝜑 → ¬ 𝑧 ∈ 𝐴) | 
| 155 | 154 | adantr 480 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ¬ 𝑧 ∈ 𝐴) | 
| 156 |  | hashf1lem2.4 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝜑 → ((♯‘𝐴) + 1) ≤ (♯‘𝐵)) | 
| 157 | 156 | adantr 480 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ((♯‘𝐴) + 1) ≤ (♯‘𝐵)) | 
| 158 |  | simpr 484 | . . . . . . . . . . . . . . . . . . . 20
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → 𝑎:𝐴–1-1→𝐵) | 
| 159 | 152, 153,
155, 157, 158 | hashf1lem1 14494 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → {𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ≈ (𝐵 ∖ ran 𝑎)) | 
| 160 |  | hasheni 14387 | . . . . . . . . . . . . . . . . . . 19
⊢ ({𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)} ≈ (𝐵 ∖ ran 𝑎) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘(𝐵 ∖ ran 𝑎))) | 
| 161 | 159, 160 | syl 17 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (♯‘(𝐵 ∖ ran 𝑎))) | 
| 162 | 151, 161 | oveq12d 7449 | . . . . . . . . . . . . . . . . 17
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ((♯‘𝐴) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) = ((♯‘ran 𝑎) + (♯‘(𝐵 ∖ ran 𝑎)))) | 
| 163 |  | f1f 6804 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑎:𝐴–1-1→𝐵 → 𝑎:𝐴⟶𝐵) | 
| 164 | 163 | frnd 6744 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑎:𝐴–1-1→𝐵 → ran 𝑎 ⊆ 𝐵) | 
| 165 | 164 | adantl 481 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ran 𝑎 ⊆ 𝐵) | 
| 166 | 153, 165 | ssfid 9301 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ran 𝑎 ∈ Fin) | 
| 167 |  | diffi 9215 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝐵 ∈ Fin → (𝐵 ∖ ran 𝑎) ∈ Fin) | 
| 168 | 153, 167 | syl 17 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (𝐵 ∖ ran 𝑎) ∈ Fin) | 
| 169 |  | disjdif 4472 | . . . . . . . . . . . . . . . . . . 19
⊢ (ran
𝑎 ∩ (𝐵 ∖ ran 𝑎)) = ∅ | 
| 170 | 169 | a1i 11 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (ran 𝑎 ∩ (𝐵 ∖ ran 𝑎)) = ∅) | 
| 171 |  | hashun 14421 | . . . . . . . . . . . . . . . . . 18
⊢ ((ran
𝑎 ∈ Fin ∧ (𝐵 ∖ ran 𝑎) ∈ Fin ∧ (ran 𝑎 ∩ (𝐵 ∖ ran 𝑎)) = ∅) → (♯‘(ran
𝑎 ∪ (𝐵 ∖ ran 𝑎))) = ((♯‘ran 𝑎) + (♯‘(𝐵 ∖ ran 𝑎)))) | 
| 172 | 166, 168,
170, 171 | syl3anc 1373 | . . . . . . . . . . . . . . . . 17
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘(ran 𝑎 ∪ (𝐵 ∖ ran 𝑎))) = ((♯‘ran 𝑎) + (♯‘(𝐵 ∖ ran 𝑎)))) | 
| 173 |  | undif 4482 | . . . . . . . . . . . . . . . . . . 19
⊢ (ran
𝑎 ⊆ 𝐵 ↔ (ran 𝑎 ∪ (𝐵 ∖ ran 𝑎)) = 𝐵) | 
| 174 | 165, 173 | sylib 218 | . . . . . . . . . . . . . . . . . 18
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (ran 𝑎 ∪ (𝐵 ∖ ran 𝑎)) = 𝐵) | 
| 175 | 174 | fveq2d 6910 | . . . . . . . . . . . . . . . . 17
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘(ran 𝑎 ∪ (𝐵 ∖ ran 𝑎))) = (♯‘𝐵)) | 
| 176 | 162, 172,
175 | 3eqtr2d 2783 | . . . . . . . . . . . . . . . 16
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → ((♯‘𝐴) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) = (♯‘𝐵)) | 
| 177 | 176 | oveq1d 7446 | . . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (((♯‘𝐴) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) − (♯‘𝐴)) = ((♯‘𝐵) − (♯‘𝐴))) | 
| 178 | 145, 177 | eqtr3d 2779 | . . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ 𝑎:𝐴–1-1→𝐵) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ((♯‘𝐵) − (♯‘𝐴))) | 
| 179 | 139, 178 | sylan2 593 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ((♯‘𝐵) − (♯‘𝐴))) | 
| 180 | 179 | oveq2d 7447 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) = 𝑎 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)})) = ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + ((♯‘𝐵) − (♯‘𝐴)))) | 
| 181 | 131, 180 | eqtrd 2777 | . . . . . . . . . . 11
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + ((♯‘𝐵) − (♯‘𝐴)))) | 
| 182 |  | hashunsng 14431 | . . . . . . . . . . . . . . 15
⊢ (𝑎 ∈ V → ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) → (♯‘(𝑦 ∪ {𝑎})) = ((♯‘𝑦) + 1))) | 
| 183 | 182 | elv 3485 | . . . . . . . . . . . . . 14
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) → (♯‘(𝑦 ∪ {𝑎})) = ((♯‘𝑦) + 1)) | 
| 184 | 183 | ad2antrl 728 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘(𝑦 ∪ {𝑎})) = ((♯‘𝑦) + 1)) | 
| 185 | 184 | oveq2d 7447 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (((♯‘𝐵) − (♯‘𝐴)) ·
(♯‘(𝑦 ∪
{𝑎}))) =
(((♯‘𝐵) −
(♯‘𝐴)) ·
((♯‘𝑦) +
1))) | 
| 186 | 79 | adantr 480 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ((♯‘𝐵) − (♯‘𝐴)) ∈ ℂ) | 
| 187 |  | simprll 779 | . . . . . . . . . . . . . . 15
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → 𝑦 ∈ Fin) | 
| 188 |  | hashcl 14395 | . . . . . . . . . . . . . . 15
⊢ (𝑦 ∈ Fin →
(♯‘𝑦) ∈
ℕ0) | 
| 189 | 187, 188 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘𝑦) ∈
ℕ0) | 
| 190 | 189 | nn0cnd 12589 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (♯‘𝑦) ∈ ℂ) | 
| 191 |  | 1cnd 11256 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → 1 ∈
ℂ) | 
| 192 | 186, 190,
191 | adddid 11285 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (((♯‘𝐵) − (♯‘𝐴)) ·
((♯‘𝑦) + 1)) =
((((♯‘𝐵)
− (♯‘𝐴))
· (♯‘𝑦))
+ (((♯‘𝐵)
− (♯‘𝐴))
· 1))) | 
| 193 | 186 | mulridd 11278 | . . . . . . . . . . . . 13
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (((♯‘𝐵) − (♯‘𝐴)) · 1) =
((♯‘𝐵) −
(♯‘𝐴))) | 
| 194 | 193 | oveq2d 7447 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ((((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) + (((♯‘𝐵) − (♯‘𝐴)) · 1)) =
((((♯‘𝐵)
− (♯‘𝐴))
· (♯‘𝑦))
+ ((♯‘𝐵)
− (♯‘𝐴)))) | 
| 195 | 185, 192,
194 | 3eqtrd 2781 | . . . . . . . . . . 11
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → (((♯‘𝐵) − (♯‘𝐴)) ·
(♯‘(𝑦 ∪
{𝑎}))) =
((((♯‘𝐵)
− (♯‘𝐴))
· (♯‘𝑦))
+ ((♯‘𝐵)
− (♯‘𝐴)))) | 
| 196 | 181, 195 | eqeq12d 2753 | . . . . . . . . . 10
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))) ↔ ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) + ((♯‘𝐵) − (♯‘𝐴))) = ((((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) + ((♯‘𝐵) − (♯‘𝐴))))) | 
| 197 | 87, 196 | imbitrrid 246 | . . . . . . . . 9
⊢ ((𝜑 ∧ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) ∧ (𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵})) → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))))) | 
| 198 | 197 | expr 456 | . . . . . . . 8
⊢ ((𝜑 ∧ (𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦)) → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → ((♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)) → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎})))))) | 
| 199 | 198 | a2d 29 | . . . . . . 7
⊢ ((𝜑 ∧ (𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦)) → (((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))) → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎})))))) | 
| 200 | 86, 199 | syl5 34 | . . . . . 6
⊢ ((𝜑 ∧ (𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦)) → ((𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))) → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎})))))) | 
| 201 | 200 | expcom 413 | . . . . 5
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) → (𝜑 → ((𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦))) → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))))))) | 
| 202 | 201 | a2d 29 | . . . 4
⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑎 ∈ 𝑦) → ((𝜑 → (𝑦 ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ 𝑦 ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘𝑦)))) → (𝜑 → ((𝑦 ∪ {𝑎}) ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ ((𝑓 ↾ 𝐴) ∈ (𝑦 ∪ {𝑎}) ∧ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵)}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘(𝑦 ∪ {𝑎}))))))) | 
| 203 | 28, 38, 48, 72, 82, 202 | findcard2s 9205 | . . 3
⊢ ({𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ∈ Fin → (𝜑 → ({𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵}))))) | 
| 204 | 10, 203 | mpcom 38 | . 2
⊢ (𝜑 → ({𝑓 ∣ 𝑓:𝐴–1-1→𝐵} ⊆ {𝑓 ∣ 𝑓:𝐴–1-1→𝐵} → (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵})))) | 
| 205 | 1, 204 | mpi 20 | 1
⊢ (𝜑 → (♯‘{𝑓 ∣ 𝑓:(𝐴 ∪ {𝑧})–1-1→𝐵}) = (((♯‘𝐵) − (♯‘𝐴)) · (♯‘{𝑓 ∣ 𝑓:𝐴–1-1→𝐵}))) |