| Step | Hyp | Ref
| Expression |
| 1 | | madebdayim 28283 |
. 2
⊢ (𝑋 ∈ (M‘𝐴) → (bday‘𝑋) ⊆ 𝐴) |
| 2 | | sseq2 3935 |
. . . . . . 7
⊢ (𝑎 = 𝑏 → ((bday‘𝑥) ⊆ 𝑎 ↔ (bday‘𝑥) ⊆ 𝑏)) |
| 3 | | fveq2 6890 |
. . . . . . . 8
⊢ (𝑎 = 𝑏 → (M‘𝑎) = (M‘𝑏)) |
| 4 | 3 | eleq2d 2846 |
. . . . . . 7
⊢ (𝑎 = 𝑏 → (𝑥 ∈ (M‘𝑎) ↔ 𝑥 ∈ (M‘𝑏))) |
| 5 | 2, 4 | imbi12d 347 |
. . . . . 6
⊢ (𝑎 = 𝑏 → (((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)) ↔ ((bday‘𝑥) ⊆ 𝑏 → 𝑥 ∈ (M‘𝑏)))) |
| 6 | 5 | ralbidv 3185 |
. . . . 5
⊢ (𝑎 = 𝑏 → (∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)) ↔ ∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑏 → 𝑥 ∈ (M‘𝑏)))) |
| 7 | | fveq2 6890 |
. . . . . . . 8
⊢ (𝑥 = 𝑦 → (bday‘𝑥) = (bday‘𝑦)) |
| 8 | 7 | sseq1d 3940 |
. . . . . . 7
⊢ (𝑥 = 𝑦 → ((bday‘𝑥) ⊆ 𝑏 ↔ (bday‘𝑦) ⊆ 𝑏)) |
| 9 | | eleq1 2848 |
. . . . . . 7
⊢ (𝑥 = 𝑦 → (𝑥 ∈ (M‘𝑏) ↔ 𝑦 ∈ (M‘𝑏))) |
| 10 | 8, 9 | imbi12d 347 |
. . . . . 6
⊢ (𝑥 = 𝑦 → (((bday‘𝑥) ⊆ 𝑏 → 𝑥 ∈ (M‘𝑏)) ↔ ((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)))) |
| 11 | 10 | cbvralvw 3240 |
. . . . 5
⊢
(∀𝑥 ∈
No ((bday‘𝑥) ⊆ 𝑏 → 𝑥 ∈ (M‘𝑏)) ↔ ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) |
| 12 | 6, 11 | bitrdi 290 |
. . . 4
⊢ (𝑎 = 𝑏 → (∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)) ↔ ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)))) |
| 13 | | sseq2 3935 |
. . . . . 6
⊢ (𝑎 = 𝐴 → ((bday‘𝑥) ⊆ 𝑎 ↔ (bday‘𝑥) ⊆ 𝐴)) |
| 14 | | fveq2 6890 |
. . . . . . 7
⊢ (𝑎 = 𝐴 → (M‘𝑎) = (M‘𝐴)) |
| 15 | 14 | eleq2d 2846 |
. . . . . 6
⊢ (𝑎 = 𝐴 → (𝑥 ∈ (M‘𝑎) ↔ 𝑥 ∈ (M‘𝐴))) |
| 16 | 13, 15 | imbi12d 347 |
. . . . 5
⊢ (𝑎 = 𝐴 → (((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)) ↔ ((bday‘𝑥) ⊆ 𝐴 → 𝑥 ∈ (M‘𝐴)))) |
| 17 | 16 | ralbidv 3185 |
. . . 4
⊢ (𝑎 = 𝐴 → (∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)) ↔ ∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝐴 → 𝑥 ∈ (M‘𝐴)))) |
| 18 | | bdayon 28147 |
. . . . . . . . 9
⊢ (bday‘𝑥) ∈ On |
| 19 | | onsseleq 6407 |
. . . . . . . . 9
⊢ (((bday‘𝑥) ∈ On ∧ 𝑎 ∈ On) → ((bday‘𝑥) ⊆ 𝑎 ↔ ((bday‘𝑥) ∈ 𝑎 ∨ (bday‘𝑥) = 𝑎))) |
| 20 | 18, 19 | mpan 703 |
. . . . . . . 8
⊢ (𝑎 ∈ On → ((bday‘𝑥) ⊆ 𝑎 ↔ ((bday‘𝑥) ∈ 𝑎 ∨ (bday‘𝑥) = 𝑎))) |
| 21 | 20 | ad2antrr 739 |
. . . . . . 7
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) ⊆ 𝑎 ↔ ((bday‘𝑥) ∈ 𝑎 ∨ (bday‘𝑥) = 𝑎))) |
| 22 | | simpll 779 |
. . . . . . . . . . 11
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ 𝑎 ∈
On) |
| 23 | | onelss 6408 |
. . . . . . . . . . . . 13
⊢ (𝑎 ∈ On → ((bday‘𝑥) ∈ 𝑎 → (bday‘𝑥) ⊆ 𝑎)) |
| 24 | 23 | ad2antrr 739 |
. . . . . . . . . . . 12
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) ∈ 𝑎 → (bday‘𝑥) ⊆ 𝑎)) |
| 25 | 24 | imp 412 |
. . . . . . . . . . 11
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → (bday‘𝑥) ⊆ 𝑎) |
| 26 | | madess 28261 |
. . . . . . . . . . 11
⊢ ((𝑎 ∈ On ∧ (bday‘𝑥) ⊆ 𝑎) → (M‘(bday‘𝑥)) ⊆ (M‘𝑎)) |
| 27 | 22, 25, 26 | syl2an2r 698 |
. . . . . . . . . 10
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → (M‘(bday‘𝑥)) ⊆ (M‘𝑎)) |
| 28 | | ssid 3931 |
. . . . . . . . . . 11
⊢ (bday‘𝑥) ⊆ (bday‘𝑥) |
| 29 | | simpr 490 |
. . . . . . . . . . . . 13
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → (bday‘𝑥) ∈ 𝑎) |
| 30 | | simplr 781 |
. . . . . . . . . . . . 13
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → 𝑥 ∈ No) |
| 31 | 29, 30 | jca 521 |
. . . . . . . . . . . 12
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → ((bday‘𝑥) ∈ 𝑎 ∧ 𝑥 ∈ No)) |
| 32 | | simpllr 788 |
. . . . . . . . . . . 12
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) |
| 33 | | sseq2 3935 |
. . . . . . . . . . . . . 14
⊢ (𝑏 = (bday‘𝑥) → ((bday‘𝑦) ⊆ 𝑏 ↔ (bday‘𝑦) ⊆ (bday‘𝑥))) |
| 34 | | fveq2 6890 |
. . . . . . . . . . . . . . 15
⊢ (𝑏 = (bday‘𝑥) → (M‘𝑏) = (M‘(bday‘𝑥))) |
| 35 | 34 | eleq2d 2846 |
. . . . . . . . . . . . . 14
⊢ (𝑏 = (bday‘𝑥) → (𝑦 ∈ (M‘𝑏) ↔ 𝑦 ∈ (M‘(bday‘𝑥)))) |
| 36 | 33, 35 | imbi12d 347 |
. . . . . . . . . . . . 13
⊢ (𝑏 = (bday‘𝑥) → (((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ↔ ((bday‘𝑦) ⊆ (bday‘𝑥) → 𝑦 ∈ (M‘(bday‘𝑥))))) |
| 37 | | fveq2 6890 |
. . . . . . . . . . . . . . 15
⊢ (𝑦 = 𝑥 → (bday‘𝑦) = (bday‘𝑥)) |
| 38 | 37 | sseq1d 3940 |
. . . . . . . . . . . . . 14
⊢ (𝑦 = 𝑥 → ((bday‘𝑦) ⊆ (bday‘𝑥) ↔ (bday‘𝑥) ⊆ (bday‘𝑥))) |
| 39 | | eleq1 2848 |
. . . . . . . . . . . . . 14
⊢ (𝑦 = 𝑥 → (𝑦 ∈ (M‘(bday‘𝑥)) ↔ 𝑥 ∈ (M‘(bday‘𝑥)))) |
| 40 | 38, 39 | imbi12d 347 |
. . . . . . . . . . . . 13
⊢ (𝑦 = 𝑥 → (((bday‘𝑦) ⊆ (bday‘𝑥) → 𝑦 ∈ (M‘(bday‘𝑥))) ↔ ((bday‘𝑥) ⊆ (bday‘𝑥) → 𝑥 ∈ (M‘(bday‘𝑥))))) |
| 41 | 36, 40 | rspc2v 3586 |
. . . . . . . . . . . 12
⊢ (((bday‘𝑥) ∈ 𝑎 ∧ 𝑥 ∈ No)
→ (∀𝑏 ∈
𝑎 ∀𝑦 ∈ No ((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) → ((bday‘𝑥) ⊆ (bday‘𝑥) → 𝑥 ∈ (M‘(bday‘𝑥))))) |
| 42 | 31, 32, 41 | sylc 66 |
. . . . . . . . . . 11
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → ((bday‘𝑥) ⊆ (bday‘𝑥) → 𝑥 ∈ (M‘(bday‘𝑥)))) |
| 43 | 28, 42 | mpi 21 |
. . . . . . . . . 10
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → 𝑥 ∈ (M‘(bday‘𝑥))) |
| 44 | 27, 43 | sseldd 3910 |
. . . . . . . . 9
⊢ ((((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
∧ (bday‘𝑥) ∈ 𝑎) → 𝑥 ∈ (M‘𝑎)) |
| 45 | 44 | ex 418 |
. . . . . . . 8
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) ∈ 𝑎 → 𝑥 ∈ (M‘𝑎))) |
| 46 | | madebdaylemlrcut 28294 |
. . . . . . . . . . . 12
⊢
((∀𝑏 ∈
(bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ ((L‘𝑥) |s
(R‘𝑥)) = 𝑥) |
| 47 | 18 | a1i 11 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ No → (bday‘𝑥) ∈ On) |
| 48 | | lltr 28257 |
. . . . . . . . . . . . . . 15
⊢
(L‘𝑥)
<<s (R‘𝑥) |
| 49 | 48 | a1i 11 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ No → (L‘𝑥) <<s (R‘𝑥)) |
| 50 | | leftssold 28266 |
. . . . . . . . . . . . . . 15
⊢
(L‘𝑥) ⊆
(O‘(bday‘𝑥)) |
| 51 | 50 | a1i 11 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ No → (L‘𝑥) ⊆ (O‘(bday‘𝑥))) |
| 52 | | rightssold 28267 |
. . . . . . . . . . . . . . 15
⊢
(R‘𝑥) ⊆
(O‘(bday‘𝑥)) |
| 53 | 52 | a1i 11 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ No → (R‘𝑥) ⊆ (O‘(bday‘𝑥))) |
| 54 | | madecut 28278 |
. . . . . . . . . . . . . 14
⊢ ((((bday‘𝑥) ∈ On ∧ (L‘𝑥) <<s (R‘𝑥)) ∧ ((L‘𝑥) ⊆ (O‘(bday‘𝑥)) ∧ (R‘𝑥) ⊆ (O‘(bday‘𝑥)))) → ((L‘𝑥) |s (R‘𝑥)) ∈ (M‘(bday‘𝑥))) |
| 55 | 47, 49, 51, 53, 54 | syl22anc 852 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ No → ((L‘𝑥) |s (R‘𝑥)) ∈ (M‘(bday‘𝑥))) |
| 56 | 55 | adantl 487 |
. . . . . . . . . . . 12
⊢
((∀𝑏 ∈
(bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ ((L‘𝑥) |s
(R‘𝑥)) ∈
(M‘(bday‘𝑥))) |
| 57 | 46, 56 | eqeltrrd 2861 |
. . . . . . . . . . 11
⊢
((∀𝑏 ∈
(bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ 𝑥 ∈
(M‘(bday‘𝑥))) |
| 58 | | raleq 3316 |
. . . . . . . . . . . . 13
⊢ ((bday‘𝑥) = 𝑎 → (∀𝑏 ∈ (bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ↔ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)))) |
| 59 | 58 | anbi1d 643 |
. . . . . . . . . . . 12
⊢ ((bday‘𝑥) = 𝑎 → ((∀𝑏 ∈ (bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
↔ (∀𝑏 ∈
𝑎 ∀𝑦 ∈ No ((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No))) |
| 60 | | fveq2 6890 |
. . . . . . . . . . . . 13
⊢ ((bday‘𝑥) = 𝑎 → (M‘(bday‘𝑥)) = (M‘𝑎)) |
| 61 | 60 | eleq2d 2846 |
. . . . . . . . . . . 12
⊢ ((bday‘𝑥) = 𝑎 → (𝑥 ∈ (M‘(bday‘𝑥)) ↔ 𝑥 ∈ (M‘𝑎))) |
| 62 | 59, 61 | imbi12d 347 |
. . . . . . . . . . 11
⊢ ((bday‘𝑥) = 𝑎 → (((∀𝑏 ∈ (bday‘𝑥)∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ 𝑥 ∈
(M‘(bday‘𝑥))) ↔ ((∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ 𝑥 ∈
(M‘𝑎)))) |
| 63 | 57, 62 | mpbii 236 |
. . . . . . . . . 10
⊢ ((bday‘𝑥) = 𝑎 → ((∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ 𝑥 ∈
(M‘𝑎))) |
| 64 | 63 | com12 33 |
. . . . . . . . 9
⊢
((∀𝑏 ∈
𝑎 ∀𝑦 ∈ No ((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) = 𝑎 → 𝑥 ∈ (M‘𝑎))) |
| 65 | 64 | adantll 727 |
. . . . . . . 8
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) = 𝑎 → 𝑥 ∈ (M‘𝑎))) |
| 66 | 45, 65 | jaod 873 |
. . . . . . 7
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ (((bday‘𝑥) ∈ 𝑎 ∨ (bday‘𝑥) = 𝑎) → 𝑥 ∈ (M‘𝑎))) |
| 67 | 21, 66 | sylbid 243 |
. . . . . 6
⊢ (((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) ∧ 𝑥 ∈ No)
→ ((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎))) |
| 68 | 67 | ralrimiva 3154 |
. . . . 5
⊢ ((𝑎 ∈ On ∧ ∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏))) → ∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎))) |
| 69 | 68 | ex 418 |
. . . 4
⊢ (𝑎 ∈ On → (∀𝑏 ∈ 𝑎 ∀𝑦 ∈ No
((bday‘𝑦) ⊆ 𝑏 → 𝑦 ∈ (M‘𝑏)) → ∀𝑥 ∈ No
((bday‘𝑥) ⊆ 𝑎 → 𝑥 ∈ (M‘𝑎)))) |
| 70 | 12, 17, 69 | tfis3 7873 |
. . 3
⊢ (𝐴 ∈ On → ∀𝑥 ∈ No ((bday‘𝑥) ⊆ 𝐴 → 𝑥 ∈ (M‘𝐴))) |
| 71 | | fveq2 6890 |
. . . . . 6
⊢ (𝑥 = 𝑋 → (bday‘𝑥) = (bday‘𝑋)) |
| 72 | 71 | sseq1d 3940 |
. . . . 5
⊢ (𝑥 = 𝑋 → ((bday‘𝑥) ⊆ 𝐴 ↔ (bday‘𝑋) ⊆ 𝐴)) |
| 73 | | eleq1 2848 |
. . . . 5
⊢ (𝑥 = 𝑋 → (𝑥 ∈ (M‘𝐴) ↔ 𝑋 ∈ (M‘𝐴))) |
| 74 | 72, 73 | imbi12d 347 |
. . . 4
⊢ (𝑥 = 𝑋 → (((bday‘𝑥) ⊆ 𝐴 → 𝑥 ∈ (M‘𝐴)) ↔ ((bday‘𝑋) ⊆ 𝐴 → 𝑋 ∈ (M‘𝐴)))) |
| 75 | 74 | rspccva 3575 |
. . 3
⊢
((∀𝑥 ∈
No ((bday‘𝑥) ⊆ 𝐴 → 𝑥 ∈ (M‘𝐴)) ∧ 𝑋 ∈ No)
→ ((bday‘𝑋) ⊆ 𝐴 → 𝑋 ∈ (M‘𝐴))) |
| 76 | 70, 75 | sylan 592 |
. 2
⊢ ((𝐴 ∈ On ∧ 𝑋 ∈ No) → ((bday‘𝑋) ⊆ 𝐴 → 𝑋 ∈ (M‘𝐴))) |
| 77 | 1, 76 | impbid2 229 |
1
⊢ ((𝐴 ∈ On ∧ 𝑋 ∈ No) → (𝑋 ∈ (M‘𝐴) ↔ (bday‘𝑋) ⊆ 𝐴)) |