| Step | Hyp | Ref
| Expression |
| 1 | | breq1 5105 |
. . . . . . . . . . . . . 14
⊢ (𝑥 = 𝑋 → (𝑥 <s 𝑧 ↔ 𝑋 <s 𝑧)) |
| 2 | 1 | anbi1d 643 |
. . . . . . . . . . . . 13
⊢ (𝑥 = 𝑋 → ((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) ↔ (𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦))) |
| 3 | 2 | imbi1d 344 |
. . . . . . . . . . . 12
⊢ (𝑥 = 𝑋 → (((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) ↔ ((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴))) |
| 4 | 3 | ralbidv 3185 |
. . . . . . . . . . 11
⊢ (𝑥 = 𝑋 → (∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) ↔ ∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴))) |
| 5 | | breq2 5106 |
. . . . . . . . . . . . . 14
⊢ (𝑦 = 𝑌 → (𝑧 <s 𝑦 ↔ 𝑧 <s 𝑌)) |
| 6 | 5 | anbi2d 642 |
. . . . . . . . . . . . 13
⊢ (𝑦 = 𝑌 → ((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦) ↔ (𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌))) |
| 7 | 6 | imbi1d 344 |
. . . . . . . . . . . 12
⊢ (𝑦 = 𝑌 → (((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) ↔ ((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴))) |
| 8 | 7 | ralbidv 3185 |
. . . . . . . . . . 11
⊢ (𝑦 = 𝑌 → (∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) ↔ ∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴))) |
| 9 | 4, 8 | rspc2v 3586 |
. . . . . . . . . 10
⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) → ∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴))) |
| 10 | | breq2 5106 |
. . . . . . . . . . . . . . . 16
⊢ (𝑧 = 𝑤 → (𝑋 <s 𝑧 ↔ 𝑋 <s 𝑤)) |
| 11 | | breq1 5105 |
. . . . . . . . . . . . . . . 16
⊢ (𝑧 = 𝑤 → (𝑧 <s 𝑌 ↔ 𝑤 <s 𝑌)) |
| 12 | 10, 11 | anbi12d 644 |
. . . . . . . . . . . . . . 15
⊢ (𝑧 = 𝑤 → ((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) ↔ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 13 | | eleq1w 2843 |
. . . . . . . . . . . . . . 15
⊢ (𝑧 = 𝑤 → (𝑧 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) |
| 14 | 12, 13 | imbi12d 347 |
. . . . . . . . . . . . . 14
⊢ (𝑧 = 𝑤 → (((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴) ↔ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → 𝑤 ∈ 𝐴))) |
| 15 | 14 | rspcv 3572 |
. . . . . . . . . . . . 13
⊢ (𝑤 ∈ No → (∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴) → ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → 𝑤 ∈ 𝐴))) |
| 16 | | bdaydm 28141 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ dom bday = No |
| 17 | 16 | sseq2i 3937 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝐴 ⊆ dom bday ↔ 𝐴 ⊆ No) |
| 18 | | bdayfun 28139 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ Fun bday |
| 19 | | funfvima2 7238 |
. . . . . . . . . . . . . . . . . . . . . 22
⊢ ((Fun
bday ∧ 𝐴 ⊆ dom bday) → (𝑤 ∈ 𝐴 → (bday‘𝑤) ∈ (bday
“ 𝐴))) |
| 20 | 18, 19 | mpan 703 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (𝐴 ⊆ dom bday → (𝑤 ∈ 𝐴 → (bday‘𝑤) ∈ (bday
“ 𝐴))) |
| 21 | 17, 20 | sylbir 238 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝐴 ⊆ No → (𝑤 ∈ 𝐴 → (bday‘𝑤) ∈ (bday
“ 𝐴))) |
| 22 | 21 | imp 412 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → (bday‘𝑤) ∈ (bday
“ 𝐴)) |
| 23 | | intss1 4922 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((bday‘𝑤) ∈ (bday
“ 𝐴) → ∩ (bday “ 𝐴) ⊆ (bday‘𝑤)) |
| 24 | 22, 23 | syl 18 |
. . . . . . . . . . . . . . . . . 18
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → ∩ (bday “ 𝐴) ⊆ (bday‘𝑤)) |
| 25 | | imassrn 6197 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ (bday “ 𝐴) ⊆ ran bday |
| 26 | | bdayrn 28143 |
. . . . . . . . . . . . . . . . . . . . 21
⊢ ran bday = On |
| 27 | 25, 26 | sseqtri 3956 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (bday “ 𝐴) ⊆ On |
| 28 | 22 | ne0d 4287 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → (bday
“ 𝐴) ≠
∅) |
| 29 | | oninton 7810 |
. . . . . . . . . . . . . . . . . . . 20
⊢ (((bday “ 𝐴) ⊆ On ∧ (bday “ 𝐴) ≠ ∅) → ∩ (bday “ 𝐴) ∈ On) |
| 30 | 27, 28, 29 | sylancr 599 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → ∩ (bday “ 𝐴) ∈ On) |
| 31 | | bdayon 28144 |
. . . . . . . . . . . . . . . . . . 19
⊢ (bday‘𝑤) ∈ On |
| 32 | | ontri1 6397 |
. . . . . . . . . . . . . . . . . . 19
⊢ ((∩ (bday “ 𝐴) ∈ On ∧ (bday‘𝑤) ∈ On) → (∩ (bday “ 𝐴) ⊆ (bday‘𝑤) ↔ ¬ (bday‘𝑤) ∈ ∩ (bday “ 𝐴))) |
| 33 | 30, 31, 32 | sylancl 598 |
. . . . . . . . . . . . . . . . . 18
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → (∩
(bday “ 𝐴) ⊆ (bday‘𝑤) ↔ ¬ (bday‘𝑤) ∈ ∩ (bday “ 𝐴))) |
| 34 | 24, 33 | mpbid 235 |
. . . . . . . . . . . . . . . . 17
⊢ ((𝐴 ⊆ No ∧ 𝑤 ∈ 𝐴) → ¬ (bday‘𝑤) ∈ ∩ (bday “ 𝐴)) |
| 35 | 34 | ex 418 |
. . . . . . . . . . . . . . . 16
⊢ (𝐴 ⊆ No → (𝑤 ∈ 𝐴 → ¬ (bday‘𝑤) ∈ ∩ (bday “ 𝐴))) |
| 36 | | eleq2 2849 |
. . . . . . . . . . . . . . . . . 18
⊢ ((bday‘𝑋) = ∩ (bday “ 𝐴) → ((bday‘𝑤) ∈ (bday‘𝑋) ↔ (bday‘𝑤) ∈ ∩ (bday “ 𝐴))) |
| 37 | 36 | notbid 321 |
. . . . . . . . . . . . . . . . 17
⊢ ((bday‘𝑋) = ∩ (bday “ 𝐴) → (¬ (bday‘𝑤) ∈ (bday‘𝑋) ↔ ¬ (bday‘𝑤) ∈ ∩ (bday “ 𝐴))) |
| 38 | 37 | biimprcd 253 |
. . . . . . . . . . . . . . . 16
⊢ (¬
(bday‘𝑤) ∈ ∩ (bday “ 𝐴) → ((bday‘𝑋) = ∩ (bday “ 𝐴) → ¬ (bday‘𝑤) ∈ (bday‘𝑋))) |
| 39 | 35, 38 | syl6 36 |
. . . . . . . . . . . . . . 15
⊢ (𝐴 ⊆ No → (𝑤 ∈ 𝐴 → ((bday‘𝑋) = ∩ (bday “ 𝐴) → ¬ (bday‘𝑤) ∈ (bday‘𝑋)))) |
| 40 | 39 | com3l 90 |
. . . . . . . . . . . . . 14
⊢ (𝑤 ∈ 𝐴 → ((bday‘𝑋) = ∩ (bday “ 𝐴) → (𝐴 ⊆ No
→ ¬ (bday‘𝑤) ∈ (bday‘𝑋)))) |
| 41 | 40 | adantrd 497 |
. . . . . . . . . . . . 13
⊢ (𝑤 ∈ 𝐴 → (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝐴 ⊆ No
→ ¬ (bday‘𝑤) ∈ (bday‘𝑋)))) |
| 42 | 15, 41 | syl8 77 |
. . . . . . . . . . . 12
⊢ (𝑤 ∈ No → (∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴) → ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝐴 ⊆ No
→ ¬ (bday‘𝑤) ∈ (bday‘𝑋)))))) |
| 43 | 42 | com35 99 |
. . . . . . . . . . 11
⊢ (𝑤 ∈ No → (∀𝑧 ∈ No
((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴) → (𝐴 ⊆ No
→ (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋)))))) |
| 44 | 43 | com4l 93 |
. . . . . . . . . 10
⊢
(∀𝑧 ∈
No ((𝑋 <s 𝑧 ∧ 𝑧 <s 𝑌) → 𝑧 ∈ 𝐴) → (𝐴 ⊆ No
→ (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝑤 ∈ No
→ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋)))))) |
| 45 | 9, 44 | syl6 36 |
. . . . . . . . 9
⊢ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) → (𝐴 ⊆ No
→ (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝑤 ∈ No
→ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋))))))) |
| 46 | 45 | com3l 90 |
. . . . . . . 8
⊢
(∀𝑥 ∈
𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴) → (𝐴 ⊆ No
→ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝑤 ∈ No
→ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋))))))) |
| 47 | 46 | impcom 413 |
. . . . . . 7
⊢ ((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) → ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (𝑤 ∈ No
→ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋)))))) |
| 48 | 47 | imp42 432 |
. . . . . 6
⊢ ((((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) ∧ 𝑤 ∈ No)
→ ((𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) → ¬ (bday‘𝑤) ∈ (bday‘𝑋))) |
| 49 | 48 | con2d 135 |
. . . . 5
⊢ ((((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) ∧ 𝑤 ∈ No)
→ ((bday‘𝑤) ∈ (bday‘𝑋) → ¬ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 50 | | 3anass 1111 |
. . . . . . 7
⊢ (((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) ↔ ((bday‘𝑤) ∈ (bday‘𝑋) ∧ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 51 | 50 | notbii 323 |
. . . . . 6
⊢ (¬
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) ↔ ¬ ((bday‘𝑤) ∈ (bday‘𝑋) ∧ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 52 | | imnan 405 |
. . . . . 6
⊢ (((bday‘𝑤) ∈ (bday‘𝑋) → ¬ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) ↔ ¬ ((bday‘𝑤) ∈ (bday‘𝑋) ∧ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 53 | 51, 52 | bitr4i 281 |
. . . . 5
⊢ (¬
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌) ↔ ((bday‘𝑤) ∈ (bday‘𝑋) → ¬ (𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌))) |
| 54 | 49, 53 | sylibr 237 |
. . . 4
⊢ ((((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) ∧ 𝑤 ∈ No)
→ ¬ ((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) |
| 55 | 54 | nrexdv 3157 |
. . 3
⊢ (((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) → ¬ ∃𝑤 ∈ No
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) |
| 56 | | ssel 3902 |
. . . . . . . . 9
⊢ (𝐴 ⊆ No → (𝑋 ∈ 𝐴 → 𝑋 ∈ No)) |
| 57 | | ssel 3902 |
. . . . . . . . 9
⊢ (𝐴 ⊆ No → (𝑌 ∈ 𝐴 → 𝑌 ∈ No)) |
| 58 | 56, 57 | anim12d 621 |
. . . . . . . 8
⊢ (𝐴 ⊆ No → ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) → (𝑋 ∈ No
∧ 𝑌 ∈ No))) |
| 59 | 58 | imp 412 |
. . . . . . 7
⊢ ((𝐴 ⊆ No ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴)) → (𝑋 ∈ No
∧ 𝑌 ∈ No)) |
| 60 | | eqtr3 2782 |
. . . . . . 7
⊢ (((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)) → (bday‘𝑋) = (bday‘𝑌)) |
| 61 | 59, 60 | anim12i 625 |
. . . . . 6
⊢ (((𝐴 ⊆ No ∧ (𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴)) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴))) → ((𝑋 ∈ No
∧ 𝑌 ∈ No) ∧ (bday‘𝑋) = (bday‘𝑌))) |
| 62 | 61 | anasss 472 |
. . . . 5
⊢ ((𝐴 ⊆ No ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) → ((𝑋 ∈ No
∧ 𝑌 ∈ No) ∧ (bday‘𝑋) = (bday‘𝑌))) |
| 63 | 62 | adantlr 728 |
. . . 4
⊢ (((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) → ((𝑋 ∈ No
∧ 𝑌 ∈ No) ∧ (bday‘𝑋) = (bday‘𝑌))) |
| 64 | | nodense 28055 |
. . . . 5
⊢ (((𝑋 ∈ No ∧ 𝑌 ∈ No)
∧ ((bday‘𝑋) = (bday‘𝑌) ∧ 𝑋 <s 𝑌)) → ∃𝑤 ∈ No
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) |
| 65 | 64 | anassrs 473 |
. . . 4
⊢ ((((𝑋 ∈ No ∧ 𝑌 ∈ No)
∧ (bday‘𝑋) = (bday‘𝑌)) ∧ 𝑋 <s 𝑌) → ∃𝑤 ∈ No
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) |
| 66 | 63, 65 | sylan 592 |
. . 3
⊢ ((((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) ∧ 𝑋 <s 𝑌) → ∃𝑤 ∈ No
((bday‘𝑤) ∈ (bday‘𝑋) ∧ 𝑋 <s 𝑤 ∧ 𝑤 <s 𝑌)) |
| 67 | 55, 66 | mtand 828 |
. 2
⊢ (((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) ∧ ((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴)))) → ¬ 𝑋 <s 𝑌) |
| 68 | 67 | ex 418 |
1
⊢ ((𝐴 ⊆ No ∧ ∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐴 ∀𝑧 ∈ No
((𝑥 <s 𝑧 ∧ 𝑧 <s 𝑦) → 𝑧 ∈ 𝐴)) → (((𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐴) ∧ ((bday‘𝑋) = ∩ (bday “ 𝐴) ∧ (bday‘𝑌) = ∩ (bday “ 𝐴))) → ¬ 𝑋 <s 𝑌)) |