| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | simp1 1136 | . . . . . . 7
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → 𝐴 <<s 𝐵) | 
| 2 |  | scutcut 27847 | . . . . . . 7
⊢ (𝐴 <<s 𝐵 → ((𝐴 |s 𝐵) ∈  No 
∧ 𝐴 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐵)) | 
| 3 | 1, 2 | syl 17 | . . . . . 6
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ((𝐴 |s 𝐵) ∈  No 
∧ 𝐴 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐵)) | 
| 4 | 3 | simp2d 1143 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → 𝐴 <<s {(𝐴 |s 𝐵)}) | 
| 5 |  | simp2 1137 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → 𝐶 <<s {(𝐴 |s 𝐵)}) | 
| 6 |  | ssltun1 27854 | . . . . 5
⊢ ((𝐴 <<s {(𝐴 |s 𝐵)} ∧ 𝐶 <<s {(𝐴 |s 𝐵)}) → (𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)}) | 
| 7 | 4, 5, 6 | syl2anc 584 | . . . 4
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)}) | 
| 8 | 3 | simp3d 1144 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → {(𝐴 |s 𝐵)} <<s 𝐵) | 
| 9 |  | simp3 1138 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → {(𝐴 |s 𝐵)} <<s 𝐷) | 
| 10 |  | ssltun2 27855 | . . . . 5
⊢ (({(𝐴 |s 𝐵)} <<s 𝐵 ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷)) | 
| 11 | 8, 9, 10 | syl2anc 584 | . . . 4
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷)) | 
| 12 |  | ovex 7465 | . . . . . 6
⊢ (𝐴 |s 𝐵) ∈ V | 
| 13 | 12 | snnz 4775 | . . . . 5
⊢ {(𝐴 |s 𝐵)} ≠ ∅ | 
| 14 |  | sslttr 27853 | . . . . 5
⊢ (((𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷) ∧ {(𝐴 |s 𝐵)} ≠ ∅) → (𝐴 ∪ 𝐶) <<s (𝐵 ∪ 𝐷)) | 
| 15 | 13, 14 | mp3an3 1451 | . . . 4
⊢ (((𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷)) → (𝐴 ∪ 𝐶) <<s (𝐵 ∪ 𝐷)) | 
| 16 | 7, 11, 15 | syl2anc 584 | . . 3
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝐴 ∪ 𝐶) <<s (𝐵 ∪ 𝐷)) | 
| 17 |  | scutval 27846 | . . 3
⊢ ((𝐴 ∪ 𝐶) <<s (𝐵 ∪ 𝐷) → ((𝐴 ∪ 𝐶) |s (𝐵 ∪ 𝐷)) = (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}))) | 
| 18 | 16, 17 | syl 17 | . 2
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ((𝐴 ∪ 𝐶) |s (𝐵 ∪ 𝐷)) = (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}))) | 
| 19 |  | vex 3483 | . . . . . . . . . 10
⊢ 𝑥 ∈ V | 
| 20 | 19 | elima 6082 | . . . . . . . . 9
⊢ (𝑥 ∈ (
bday  “ {𝑦
∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ ∃𝑧 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}𝑧 bday 𝑥) | 
| 21 |  | sneq 4635 | . . . . . . . . . . . 12
⊢ (𝑦 = 𝑧 → {𝑦} = {𝑧}) | 
| 22 | 21 | breq2d 5154 | . . . . . . . . . . 11
⊢ (𝑦 = 𝑧 → ((𝐴 ∪ 𝐶) <<s {𝑦} ↔ (𝐴 ∪ 𝐶) <<s {𝑧})) | 
| 23 | 21 | breq1d 5152 | . . . . . . . . . . 11
⊢ (𝑦 = 𝑧 → ({𝑦} <<s (𝐵 ∪ 𝐷) ↔ {𝑧} <<s (𝐵 ∪ 𝐷))) | 
| 24 | 22, 23 | anbi12d 632 | . . . . . . . . . 10
⊢ (𝑦 = 𝑧 → (((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷)) ↔ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)))) | 
| 25 | 24 | rexrab 3701 | . . . . . . . . 9
⊢
(∃𝑧 ∈
{𝑦 ∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}𝑧 bday 𝑥 ↔ ∃𝑧 ∈ 
No  (((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)) ∧ 𝑧 bday 𝑥)) | 
| 26 | 20, 25 | bitri 275 | . . . . . . . 8
⊢ (𝑥 ∈ (
bday  “ {𝑦
∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ ∃𝑧 ∈  No 
(((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)) ∧ 𝑧 bday 𝑥)) | 
| 27 |  | simplr 768 | . . . . . . . . . . . . 13
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → 𝑧 ∈  No
) | 
| 28 |  | bdayfn 27819 | . . . . . . . . . . . . . 14
⊢  bday  Fn  No | 
| 29 |  | fnbrfvb 6958 | . . . . . . . . . . . . . 14
⊢ (( bday  Fn  No  ∧ 𝑧 ∈ 
No ) → (( bday ‘𝑧) = 𝑥 ↔ 𝑧 bday 𝑥)) | 
| 30 | 28, 29 | mpan 690 | . . . . . . . . . . . . 13
⊢ (𝑧 ∈ 
No  → (( bday ‘𝑧) = 𝑥 ↔ 𝑧 bday 𝑥)) | 
| 31 | 27, 30 | syl 17 | . . . . . . . . . . . 12
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → (( bday
‘𝑧) = 𝑥 ↔ 𝑧 bday 𝑥)) | 
| 32 |  | simpll1 1212 | . . . . . . . . . . . . . . 15
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → 𝐴 <<s 𝐵) | 
| 33 |  | scutbday 27850 | . . . . . . . . . . . . . . 15
⊢ (𝐴 <<s 𝐵 → ( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ (𝐴
<<s {𝑦} ∧ {𝑦} <<s 𝐵)})) | 
| 34 | 32, 33 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → ( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ (𝐴
<<s {𝑦} ∧ {𝑦} <<s 𝐵)})) | 
| 35 |  | simprl 770 | . . . . . . . . . . . . . . . . . . 19
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → (𝐴 ∪ 𝐶) <<s {𝑧}) | 
| 36 |  | ssun1 4177 | . . . . . . . . . . . . . . . . . . . 20
⊢ 𝐴 ⊆ (𝐴 ∪ 𝐶) | 
| 37 |  | sssslt1 27841 | . . . . . . . . . . . . . . . . . . . 20
⊢ (((𝐴 ∪ 𝐶) <<s {𝑧} ∧ 𝐴 ⊆ (𝐴 ∪ 𝐶)) → 𝐴 <<s {𝑧}) | 
| 38 | 36, 37 | mpan2 691 | . . . . . . . . . . . . . . . . . . 19
⊢ ((𝐴 ∪ 𝐶) <<s {𝑧} → 𝐴 <<s {𝑧}) | 
| 39 | 35, 38 | syl 17 | . . . . . . . . . . . . . . . . . 18
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → 𝐴 <<s {𝑧}) | 
| 40 |  | simprr 772 | . . . . . . . . . . . . . . . . . . 19
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → {𝑧} <<s (𝐵 ∪ 𝐷)) | 
| 41 |  | ssun1 4177 | . . . . . . . . . . . . . . . . . . . 20
⊢ 𝐵 ⊆ (𝐵 ∪ 𝐷) | 
| 42 |  | sssslt2 27842 | . . . . . . . . . . . . . . . . . . . 20
⊢ (({𝑧} <<s (𝐵 ∪ 𝐷) ∧ 𝐵 ⊆ (𝐵 ∪ 𝐷)) → {𝑧} <<s 𝐵) | 
| 43 | 41, 42 | mpan2 691 | . . . . . . . . . . . . . . . . . . 19
⊢ ({𝑧} <<s (𝐵 ∪ 𝐷) → {𝑧} <<s 𝐵) | 
| 44 | 40, 43 | syl 17 | . . . . . . . . . . . . . . . . . 18
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → {𝑧} <<s 𝐵) | 
| 45 | 39, 44 | jca 511 | . . . . . . . . . . . . . . . . 17
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → (𝐴 <<s {𝑧} ∧ {𝑧} <<s 𝐵)) | 
| 46 | 21 | breq2d 5154 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 = 𝑧 → (𝐴 <<s {𝑦} ↔ 𝐴 <<s {𝑧})) | 
| 47 | 21 | breq1d 5152 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 = 𝑧 → ({𝑦} <<s 𝐵 ↔ {𝑧} <<s 𝐵)) | 
| 48 | 46, 47 | anbi12d 632 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑦 = 𝑧 → ((𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵) ↔ (𝐴 <<s {𝑧} ∧ {𝑧} <<s 𝐵))) | 
| 49 | 48 | elrab 3691 | . . . . . . . . . . . . . . . . 17
⊢ (𝑧 ∈ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)} ↔ (𝑧 ∈  No 
∧ (𝐴 <<s {𝑧} ∧ {𝑧} <<s 𝐵))) | 
| 50 | 27, 45, 49 | sylanbrc 583 | . . . . . . . . . . . . . . . 16
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → 𝑧 ∈ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)}) | 
| 51 |  | ssrab2 4079 | . . . . . . . . . . . . . . . . 17
⊢ {𝑦 ∈ 
No  ∣ (𝐴
<<s {𝑦} ∧ {𝑦} <<s 𝐵)} ⊆  No | 
| 52 |  | fnfvima 7254 | . . . . . . . . . . . . . . . . 17
⊢ (( bday  Fn  No  ∧ {𝑦 ∈ 
No  ∣ (𝐴
<<s {𝑦} ∧ {𝑦} <<s 𝐵)} ⊆  No 
∧ 𝑧 ∈ {𝑦 ∈ 
No  ∣ (𝐴
<<s {𝑦} ∧ {𝑦} <<s 𝐵)}) → ( bday
‘𝑧) ∈
( bday  “ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)})) | 
| 53 | 28, 51, 52 | mp3an12 1452 | . . . . . . . . . . . . . . . 16
⊢ (𝑧 ∈ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)} → ( bday
‘𝑧) ∈
( bday  “ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)})) | 
| 54 | 50, 53 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → ( bday
‘𝑧) ∈
( bday  “ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)})) | 
| 55 |  | intss1 4962 | . . . . . . . . . . . . . . 15
⊢ (( bday ‘𝑧) ∈ ( bday 
“ {𝑦 ∈  No  ∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)}) → ∩
( bday  “ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)}) ⊆ ( bday
‘𝑧)) | 
| 56 | 54, 55 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → ∩
( bday  “ {𝑦 ∈  No 
∣ (𝐴 <<s {𝑦} ∧ {𝑦} <<s 𝐵)}) ⊆ ( bday
‘𝑧)) | 
| 57 | 34, 56 | eqsstrd 4017 | . . . . . . . . . . . . 13
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → ( bday
‘(𝐴 |s 𝐵)) ⊆ ( bday ‘𝑧)) | 
| 58 |  | sseq2 4009 | . . . . . . . . . . . . . . 15
⊢ (( bday ‘𝑧) = 𝑥 → (( bday
‘(𝐴 |s 𝐵)) ⊆ ( bday ‘𝑧) ↔ ( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥)) | 
| 59 | 58 | biimpd 229 | . . . . . . . . . . . . . 14
⊢ (( bday ‘𝑧) = 𝑥 → (( bday
‘(𝐴 |s 𝐵)) ⊆ ( bday ‘𝑧) → ( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥)) | 
| 60 | 59 | com12 32 | . . . . . . . . . . . . 13
⊢ (( bday ‘(𝐴 |s 𝐵)) ⊆ ( bday
‘𝑧) →
(( bday ‘𝑧) = 𝑥 → ( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥)) | 
| 61 | 57, 60 | syl 17 | . . . . . . . . . . . 12
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → (( bday
‘𝑧) = 𝑥 → (
bday ‘(𝐴 |s
𝐵)) ⊆ 𝑥)) | 
| 62 | 31, 61 | sylbird 260 | . . . . . . . . . . 11
⊢ ((((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
∧ ((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷))) → (𝑧 bday 𝑥 → (
bday ‘(𝐴 |s
𝐵)) ⊆ 𝑥)) | 
| 63 | 62 | ex 412 | . . . . . . . . . 10
⊢ (((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
→ (((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)) → (𝑧 bday 𝑥 → (
bday ‘(𝐴 |s
𝐵)) ⊆ 𝑥))) | 
| 64 | 63 | impd 410 | . . . . . . . . 9
⊢ (((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) ∧ 𝑧 ∈  No )
→ ((((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)) ∧ 𝑧 bday 𝑥) → (
bday ‘(𝐴 |s
𝐵)) ⊆ 𝑥)) | 
| 65 | 64 | rexlimdva 3154 | . . . . . . . 8
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (∃𝑧 ∈  No 
(((𝐴 ∪ 𝐶) <<s {𝑧} ∧ {𝑧} <<s (𝐵 ∪ 𝐷)) ∧ 𝑧 bday 𝑥) → (
bday ‘(𝐴 |s
𝐵)) ⊆ 𝑥)) | 
| 66 | 26, 65 | biimtrid 242 | . . . . . . 7
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝑥 ∈ ( bday 
“ {𝑦 ∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) → ( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥)) | 
| 67 | 66 | ralrimiv 3144 | . . . . . 6
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ∀𝑥 ∈ ( bday 
“ {𝑦 ∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥) | 
| 68 |  | ssint 4963 | . . . . . 6
⊢ (( bday ‘(𝐴 |s 𝐵)) ⊆ ∩
( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ ∀𝑥 ∈ ( bday 
“ {𝑦 ∈  No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})( bday
‘(𝐴 |s 𝐵)) ⊆ 𝑥) | 
| 69 | 67, 68 | sylibr 234 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ( bday
‘(𝐴 |s 𝐵)) ⊆ ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 70 | 3 | simp1d 1142 | . . . . . . . 8
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝐴 |s 𝐵) ∈  No
) | 
| 71 | 7, 11 | jca 511 | . . . . . . . 8
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ((𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷))) | 
| 72 |  | sneq 4635 | . . . . . . . . . . 11
⊢ (𝑦 = (𝐴 |s 𝐵) → {𝑦} = {(𝐴 |s 𝐵)}) | 
| 73 | 72 | breq2d 5154 | . . . . . . . . . 10
⊢ (𝑦 = (𝐴 |s 𝐵) → ((𝐴 ∪ 𝐶) <<s {𝑦} ↔ (𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)})) | 
| 74 | 72 | breq1d 5152 | . . . . . . . . . 10
⊢ (𝑦 = (𝐴 |s 𝐵) → ({𝑦} <<s (𝐵 ∪ 𝐷) ↔ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷))) | 
| 75 | 73, 74 | anbi12d 632 | . . . . . . . . 9
⊢ (𝑦 = (𝐴 |s 𝐵) → (((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷)) ↔ ((𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷)))) | 
| 76 | 75 | elrab 3691 | . . . . . . . 8
⊢ ((𝐴 |s 𝐵) ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ↔ ((𝐴 |s 𝐵) ∈  No 
∧ ((𝐴 ∪ 𝐶) <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s (𝐵 ∪ 𝐷)))) | 
| 77 | 70, 71, 76 | sylanbrc 583 | . . . . . . 7
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝐴 |s 𝐵) ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) | 
| 78 |  | ssrab2 4079 | . . . . . . . 8
⊢ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ⊆  No | 
| 79 |  | fnfvima 7254 | . . . . . . . 8
⊢ (( bday  Fn  No  ∧ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ⊆  No
 ∧ (𝐴 |s 𝐵) ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) → ( bday
‘(𝐴 |s 𝐵)) ∈ ( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 80 | 28, 78, 79 | mp3an12 1452 | . . . . . . 7
⊢ ((𝐴 |s 𝐵) ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} → ( bday
‘(𝐴 |s 𝐵)) ∈ ( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 81 | 77, 80 | syl 17 | . . . . . 6
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ( bday
‘(𝐴 |s 𝐵)) ∈ ( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 82 |  | intss1 4962 | . . . . . 6
⊢ (( bday ‘(𝐴 |s 𝐵)) ∈ ( bday
 “ {𝑦 ∈
 No  ∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) → ∩
( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ⊆ ( bday
‘(𝐴 |s 𝐵))) | 
| 83 | 81, 82 | syl 17 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ∩ ( bday  “ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ⊆ ( bday
‘(𝐴 |s 𝐵))) | 
| 84 | 69, 83 | eqssd 4000 | . . . 4
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 85 |  | conway 27845 | . . . . . 6
⊢ ((𝐴 ∪ 𝐶) <<s (𝐵 ∪ 𝐷) → ∃!𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 86 | 16, 85 | syl 17 | . . . . 5
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ∃!𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) | 
| 87 |  | fveqeq2 6914 | . . . . . 6
⊢ (𝑥 = (𝐴 |s 𝐵) → (( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ ( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}))) | 
| 88 | 87 | riota2 7414 | . . . . 5
⊢ (((𝐴 |s 𝐵) ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ∧ ∃!𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) → (( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) = (𝐴 |s 𝐵))) | 
| 89 | 77, 86, 88 | syl2anc 584 | . . . 4
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (( bday
‘(𝐴 |s 𝐵)) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}) ↔ (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) = (𝐴 |s 𝐵))) | 
| 90 | 84, 89 | mpbid 232 | . . 3
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))})) = (𝐴 |s 𝐵)) | 
| 91 | 90 | eqcomd 2742 | . 2
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → (𝐴 |s 𝐵) = (℩𝑥 ∈ {𝑦 ∈  No 
∣ ((𝐴 ∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))} ( bday
‘𝑥) = ∩ ( bday  “ {𝑦 ∈ 
No  ∣ ((𝐴
∪ 𝐶) <<s {𝑦} ∧ {𝑦} <<s (𝐵 ∪ 𝐷))}))) | 
| 92 | 18, 91 | eqtr4d 2779 | 1
⊢ ((𝐴 <<s 𝐵 ∧ 𝐶 <<s {(𝐴 |s 𝐵)} ∧ {(𝐴 |s 𝐵)} <<s 𝐷) → ((𝐴 ∪ 𝐶) |s (𝐵 ∪ 𝐷)) = (𝐴 |s 𝐵)) |