| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | oveq1 7439 | . . 3
⊢ (𝑥 = 𝑥𝑂 → (𝑥 ·s 𝑦) = (𝑥𝑂 ·s
𝑦)) | 
| 2 |  | oveq2 7440 | . . 3
⊢ (𝑥 = 𝑥𝑂 → (𝑦 ·s 𝑥) = (𝑦 ·s 𝑥𝑂)) | 
| 3 | 1, 2 | eqeq12d 2752 | . 2
⊢ (𝑥 = 𝑥𝑂 → ((𝑥 ·s 𝑦) = (𝑦 ·s 𝑥) ↔ (𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂))) | 
| 4 |  | oveq2 7440 | . . 3
⊢ (𝑦 = 𝑦𝑂 → (𝑥𝑂
·s 𝑦) =
(𝑥𝑂
·s 𝑦𝑂)) | 
| 5 |  | oveq1 7439 | . . 3
⊢ (𝑦 = 𝑦𝑂 → (𝑦 ·s 𝑥𝑂) = (𝑦𝑂
·s 𝑥𝑂)) | 
| 6 | 4, 5 | eqeq12d 2752 | . 2
⊢ (𝑦 = 𝑦𝑂 → ((𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
↔ (𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂))) | 
| 7 |  | oveq1 7439 | . . 3
⊢ (𝑥 = 𝑥𝑂 → (𝑥 ·s 𝑦𝑂) = (𝑥𝑂
·s 𝑦𝑂)) | 
| 8 |  | oveq2 7440 | . . 3
⊢ (𝑥 = 𝑥𝑂 → (𝑦𝑂
·s 𝑥) =
(𝑦𝑂
·s 𝑥𝑂)) | 
| 9 | 7, 8 | eqeq12d 2752 | . 2
⊢ (𝑥 = 𝑥𝑂 → ((𝑥 ·s 𝑦𝑂) = (𝑦𝑂
·s 𝑥)
↔ (𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂))) | 
| 10 |  | oveq1 7439 | . . 3
⊢ (𝑥 = 𝐴 → (𝑥 ·s 𝑦) = (𝐴 ·s 𝑦)) | 
| 11 |  | oveq2 7440 | . . 3
⊢ (𝑥 = 𝐴 → (𝑦 ·s 𝑥) = (𝑦 ·s 𝐴)) | 
| 12 | 10, 11 | eqeq12d 2752 | . 2
⊢ (𝑥 = 𝐴 → ((𝑥 ·s 𝑦) = (𝑦 ·s 𝑥) ↔ (𝐴 ·s 𝑦) = (𝑦 ·s 𝐴))) | 
| 13 |  | oveq2 7440 | . . 3
⊢ (𝑦 = 𝐵 → (𝐴 ·s 𝑦) = (𝐴 ·s 𝐵)) | 
| 14 |  | oveq1 7439 | . . 3
⊢ (𝑦 = 𝐵 → (𝑦 ·s 𝐴) = (𝐵 ·s 𝐴)) | 
| 15 | 13, 14 | eqeq12d 2752 | . 2
⊢ (𝑦 = 𝐵 → ((𝐴 ·s 𝑦) = (𝑦 ·s 𝐴) ↔ (𝐴 ·s 𝐵) = (𝐵 ·s 𝐴))) | 
| 16 |  | oveq1 7439 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑝 → (𝑥𝑂 ·s
𝑦) = (𝑝 ·s 𝑦)) | 
| 17 |  | oveq2 7440 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑝 → (𝑦 ·s 𝑥𝑂) = (𝑦 ·s 𝑝)) | 
| 18 | 16, 17 | eqeq12d 2752 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑝 → ((𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂) ↔ (𝑝 ·s 𝑦) = (𝑦 ·s 𝑝))) | 
| 19 |  | simplr2 1216 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))(𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂)) | 
| 20 |  | simprl 770 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑝 ∈ ( L ‘𝑥)) | 
| 21 |  | elun1 4181 | . . . . . . . . . . . . . . 15
⊢ (𝑝 ∈ ( L ‘𝑥) → 𝑝 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 22 | 20, 21 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑝 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 23 | 18, 19, 22 | rspcdva 3622 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑝 ·s 𝑦) = (𝑦 ·s 𝑝)) | 
| 24 |  | oveq2 7440 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑞 → (𝑥 ·s 𝑦𝑂) = (𝑥 ·s 𝑞)) | 
| 25 |  | oveq1 7439 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑞 → (𝑦𝑂 ·s
𝑥) = (𝑞 ·s 𝑥)) | 
| 26 | 24, 25 | eqeq12d 2752 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑞 → ((𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥) ↔ (𝑥 ·s 𝑞) = (𝑞 ·s 𝑥))) | 
| 27 |  | simplr3 1217 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥)) | 
| 28 |  | simprr 772 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑞 ∈ ( L ‘𝑦)) | 
| 29 |  | elun1 4181 | . . . . . . . . . . . . . . 15
⊢ (𝑞 ∈ ( L ‘𝑦) → 𝑞 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 30 | 28, 29 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑞 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 31 | 26, 27, 30 | rspcdva 3622 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑥 ·s 𝑞) = (𝑞 ·s 𝑥)) | 
| 32 | 23, 31 | oveq12d 7450 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) = ((𝑦 ·s 𝑝) +s (𝑞 ·s 𝑥))) | 
| 33 |  | simpllr 775 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑦 ∈  No
) | 
| 34 |  | leftssno 27920 | . . . . . . . . . . . . . . 15
⊢ ( L
‘𝑥) ⊆  No | 
| 35 | 34, 20 | sselid 3980 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑝 ∈  No
) | 
| 36 | 33, 35 | mulscld 28162 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑦 ·s 𝑝) ∈  No
) | 
| 37 |  | leftssno 27920 | . . . . . . . . . . . . . . 15
⊢ ( L
‘𝑦) ⊆  No | 
| 38 | 37, 28 | sselid 3980 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑞 ∈  No
) | 
| 39 |  | simplll 774 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → 𝑥 ∈  No
) | 
| 40 | 38, 39 | mulscld 28162 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑞 ·s 𝑥) ∈  No
) | 
| 41 | 36, 40 | addscomd 28001 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ((𝑦 ·s 𝑝) +s (𝑞 ·s 𝑥)) = ((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝))) | 
| 42 | 32, 41 | eqtrd 2776 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) = ((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝))) | 
| 43 |  | oveq1 7439 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑝 → (𝑥𝑂 ·s
𝑦𝑂) =
(𝑝 ·s
𝑦𝑂)) | 
| 44 |  | oveq2 7440 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑝 → (𝑦𝑂 ·s
𝑥𝑂) =
(𝑦𝑂
·s 𝑝)) | 
| 45 | 43, 44 | eqeq12d 2752 | . . . . . . . . . . . 12
⊢ (𝑥𝑂 = 𝑝 → ((𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ↔ (𝑝 ·s 𝑦𝑂) = (𝑦𝑂
·s 𝑝))) | 
| 46 |  | oveq2 7440 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑞 → (𝑝 ·s 𝑦𝑂) = (𝑝 ·s 𝑞)) | 
| 47 |  | oveq1 7439 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑞 → (𝑦𝑂 ·s
𝑝) = (𝑞 ·s 𝑝)) | 
| 48 | 46, 47 | eqeq12d 2752 | . . . . . . . . . . . 12
⊢ (𝑦𝑂 = 𝑞 → ((𝑝 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑝) ↔ (𝑝 ·s 𝑞) = (𝑞 ·s 𝑝))) | 
| 49 |  | simplr1 1215 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂)) | 
| 50 | 45, 48, 49, 22, 30 | rspc2dv 3636 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑝 ·s 𝑞) = (𝑞 ·s 𝑝)) | 
| 51 | 42, 50 | oveq12d 7450 | . . . . . . . . . 10
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞)) = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))) | 
| 52 | 51 | eqeq2d 2747 | . . . . . . . . 9
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑝 ∈ ( L ‘𝑥) ∧ 𝑞 ∈ ( L ‘𝑦))) → (𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞)) ↔ 𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝)))) | 
| 53 | 52 | 2rexbidva 3219 | . . . . . . . 8
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞)) ↔ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝)))) | 
| 54 |  | rexcom 3289 | . . . . . . . 8
⊢
(∃𝑝 ∈ ( L
‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝)) ↔ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))) | 
| 55 | 53, 54 | bitrdi 287 | . . . . . . 7
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞)) ↔ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝)))) | 
| 56 | 55 | abbidv 2807 | . . . . . 6
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → {𝑎 ∣ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞))} = {𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))}) | 
| 57 |  | oveq1 7439 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑟 → (𝑥𝑂 ·s
𝑦) = (𝑟 ·s 𝑦)) | 
| 58 |  | oveq2 7440 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑟 → (𝑦 ·s 𝑥𝑂) = (𝑦 ·s 𝑟)) | 
| 59 | 57, 58 | eqeq12d 2752 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑟 → ((𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂) ↔ (𝑟 ·s 𝑦) = (𝑦 ·s 𝑟))) | 
| 60 |  | simplr2 1216 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))(𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂)) | 
| 61 |  | simprl 770 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑟 ∈ ( R ‘𝑥)) | 
| 62 |  | elun2 4182 | . . . . . . . . . . . . . . 15
⊢ (𝑟 ∈ ( R ‘𝑥) → 𝑟 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 63 | 61, 62 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑟 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 64 | 59, 60, 63 | rspcdva 3622 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑟 ·s 𝑦) = (𝑦 ·s 𝑟)) | 
| 65 |  | oveq2 7440 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑠 → (𝑥 ·s 𝑦𝑂) = (𝑥 ·s 𝑠)) | 
| 66 |  | oveq1 7439 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑠 → (𝑦𝑂 ·s
𝑥) = (𝑠 ·s 𝑥)) | 
| 67 | 65, 66 | eqeq12d 2752 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑠 → ((𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥) ↔ (𝑥 ·s 𝑠) = (𝑠 ·s 𝑥))) | 
| 68 |  | simplr3 1217 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥)) | 
| 69 |  | simprr 772 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑠 ∈ ( R ‘𝑦)) | 
| 70 |  | elun2 4182 | . . . . . . . . . . . . . . 15
⊢ (𝑠 ∈ ( R ‘𝑦) → 𝑠 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 71 | 69, 70 | syl 17 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑠 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 72 | 67, 68, 71 | rspcdva 3622 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑥 ·s 𝑠) = (𝑠 ·s 𝑥)) | 
| 73 | 64, 72 | oveq12d 7450 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) = ((𝑦 ·s 𝑟) +s (𝑠 ·s 𝑥))) | 
| 74 |  | simpllr 775 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑦 ∈  No
) | 
| 75 |  | rightssno 27921 | . . . . . . . . . . . . . . 15
⊢ ( R
‘𝑥) ⊆  No | 
| 76 | 75, 61 | sselid 3980 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑟 ∈  No
) | 
| 77 | 74, 76 | mulscld 28162 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑦 ·s 𝑟) ∈  No
) | 
| 78 |  | rightssno 27921 | . . . . . . . . . . . . . . 15
⊢ ( R
‘𝑦) ⊆  No | 
| 79 | 78, 69 | sselid 3980 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑠 ∈  No
) | 
| 80 |  | simplll 774 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → 𝑥 ∈  No
) | 
| 81 | 79, 80 | mulscld 28162 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑠 ·s 𝑥) ∈  No
) | 
| 82 | 77, 81 | addscomd 28001 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ((𝑦 ·s 𝑟) +s (𝑠 ·s 𝑥)) = ((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟))) | 
| 83 | 73, 82 | eqtrd 2776 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) = ((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟))) | 
| 84 |  | oveq1 7439 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑟 → (𝑥𝑂 ·s
𝑦𝑂) =
(𝑟 ·s
𝑦𝑂)) | 
| 85 |  | oveq2 7440 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑟 → (𝑦𝑂 ·s
𝑥𝑂) =
(𝑦𝑂
·s 𝑟)) | 
| 86 | 84, 85 | eqeq12d 2752 | . . . . . . . . . . . 12
⊢ (𝑥𝑂 = 𝑟 → ((𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ↔ (𝑟 ·s 𝑦𝑂) = (𝑦𝑂
·s 𝑟))) | 
| 87 |  | oveq2 7440 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑠 → (𝑟 ·s 𝑦𝑂) = (𝑟 ·s 𝑠)) | 
| 88 |  | oveq1 7439 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑠 → (𝑦𝑂 ·s
𝑟) = (𝑠 ·s 𝑟)) | 
| 89 | 87, 88 | eqeq12d 2752 | . . . . . . . . . . . 12
⊢ (𝑦𝑂 = 𝑠 → ((𝑟 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑟) ↔ (𝑟 ·s 𝑠) = (𝑠 ·s 𝑟))) | 
| 90 |  | simplr1 1215 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂)) | 
| 91 | 86, 89, 90, 63, 71 | rspc2dv 3636 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑟 ·s 𝑠) = (𝑠 ·s 𝑟)) | 
| 92 | 83, 91 | oveq12d 7450 | . . . . . . . . . 10
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠)) = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))) | 
| 93 | 92 | eqeq2d 2747 | . . . . . . . . 9
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑟 ∈ ( R ‘𝑥) ∧ 𝑠 ∈ ( R ‘𝑦))) → (𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠)) ↔ 𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟)))) | 
| 94 | 93 | 2rexbidva 3219 | . . . . . . . 8
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠)) ↔ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟)))) | 
| 95 |  | rexcom 3289 | . . . . . . . 8
⊢
(∃𝑟 ∈ ( R
‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟)) ↔ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))) | 
| 96 | 94, 95 | bitrdi 287 | . . . . . . 7
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠)) ↔ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟)))) | 
| 97 | 96 | abbidv 2807 | . . . . . 6
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → {𝑏 ∣ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠))} = {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))}) | 
| 98 | 56, 97 | uneq12d 4168 | . . . . 5
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → ({𝑎 ∣ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞))} ∪ {𝑏 ∣ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠))}) = ({𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))} ∪ {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))})) | 
| 99 |  | oveq1 7439 | . . . . . . . . . . . . . . . 16
⊢ (𝑥𝑂 = 𝑡 → (𝑥𝑂 ·s
𝑦) = (𝑡 ·s 𝑦)) | 
| 100 |  | oveq2 7440 | . . . . . . . . . . . . . . . 16
⊢ (𝑥𝑂 = 𝑡 → (𝑦 ·s 𝑥𝑂) = (𝑦 ·s 𝑡)) | 
| 101 | 99, 100 | eqeq12d 2752 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑡 → ((𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂) ↔ (𝑡 ·s 𝑦) = (𝑦 ·s 𝑡))) | 
| 102 |  | simplr2 1216 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))(𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂)) | 
| 103 |  | simprl 770 | . . . . . . . . . . . . . . . 16
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑡 ∈ ( L ‘𝑥)) | 
| 104 |  | elun1 4181 | . . . . . . . . . . . . . . . 16
⊢ (𝑡 ∈ ( L ‘𝑥) → 𝑡 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 105 | 103, 104 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑡 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 106 | 101, 102,
105 | rspcdva 3622 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑡 ·s 𝑦) = (𝑦 ·s 𝑡)) | 
| 107 |  | oveq2 7440 | . . . . . . . . . . . . . . . 16
⊢ (𝑦𝑂 = 𝑢 → (𝑥 ·s 𝑦𝑂) = (𝑥 ·s 𝑢)) | 
| 108 |  | oveq1 7439 | . . . . . . . . . . . . . . . 16
⊢ (𝑦𝑂 = 𝑢 → (𝑦𝑂 ·s
𝑥) = (𝑢 ·s 𝑥)) | 
| 109 | 107, 108 | eqeq12d 2752 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑢 → ((𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥) ↔ (𝑥 ·s 𝑢) = (𝑢 ·s 𝑥))) | 
| 110 |  | simplr3 1217 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥)) | 
| 111 |  | simprr 772 | . . . . . . . . . . . . . . . 16
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑢 ∈ ( R ‘𝑦)) | 
| 112 |  | elun2 4182 | . . . . . . . . . . . . . . . 16
⊢ (𝑢 ∈ ( R ‘𝑦) → 𝑢 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 113 | 111, 112 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑢 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 114 | 109, 110,
113 | rspcdva 3622 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑥 ·s 𝑢) = (𝑢 ·s 𝑥)) | 
| 115 | 106, 114 | oveq12d 7450 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) = ((𝑦 ·s 𝑡) +s (𝑢 ·s 𝑥))) | 
| 116 |  | simpllr 775 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑦 ∈  No
) | 
| 117 | 34, 103 | sselid 3980 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑡 ∈  No
) | 
| 118 | 116, 117 | mulscld 28162 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑦 ·s 𝑡) ∈  No
) | 
| 119 | 78, 111 | sselid 3980 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑢 ∈  No
) | 
| 120 |  | simplll 774 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → 𝑥 ∈  No
) | 
| 121 | 119, 120 | mulscld 28162 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑢 ·s 𝑥) ∈  No
) | 
| 122 | 118, 121 | addscomd 28001 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ((𝑦 ·s 𝑡) +s (𝑢 ·s 𝑥)) = ((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡))) | 
| 123 | 115, 122 | eqtrd 2776 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) = ((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡))) | 
| 124 |  | oveq1 7439 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑡 → (𝑥𝑂 ·s
𝑦𝑂) =
(𝑡 ·s
𝑦𝑂)) | 
| 125 |  | oveq2 7440 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑡 → (𝑦𝑂 ·s
𝑥𝑂) =
(𝑦𝑂
·s 𝑡)) | 
| 126 | 124, 125 | eqeq12d 2752 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑡 → ((𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ↔ (𝑡 ·s 𝑦𝑂) = (𝑦𝑂
·s 𝑡))) | 
| 127 |  | oveq2 7440 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑢 → (𝑡 ·s 𝑦𝑂) = (𝑡 ·s 𝑢)) | 
| 128 |  | oveq1 7439 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑢 → (𝑦𝑂 ·s
𝑡) = (𝑢 ·s 𝑡)) | 
| 129 | 127, 128 | eqeq12d 2752 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑢 → ((𝑡 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑡) ↔ (𝑡 ·s 𝑢) = (𝑢 ·s 𝑡))) | 
| 130 |  | simplr1 1215 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂)) | 
| 131 | 126, 129,
130, 105, 113 | rspc2dv 3636 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑡 ·s 𝑢) = (𝑢 ·s 𝑡)) | 
| 132 | 123, 131 | oveq12d 7450 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢)) = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))) | 
| 133 | 132 | eqeq2d 2747 | . . . . . . . . . 10
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑡 ∈ ( L ‘𝑥) ∧ 𝑢 ∈ ( R ‘𝑦))) → (𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢)) ↔ 𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡)))) | 
| 134 | 133 | 2rexbidva 3219 | . . . . . . . . 9
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢)) ↔ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡)))) | 
| 135 |  | rexcom 3289 | . . . . . . . . 9
⊢
(∃𝑡 ∈ ( L
‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡)) ↔ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))) | 
| 136 | 134, 135 | bitrdi 287 | . . . . . . . 8
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢)) ↔ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡)))) | 
| 137 | 136 | abbidv 2807 | . . . . . . 7
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → {𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} = {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}) | 
| 138 |  | oveq1 7439 | . . . . . . . . . . . . . . . 16
⊢ (𝑥𝑂 = 𝑣 → (𝑥𝑂 ·s
𝑦) = (𝑣 ·s 𝑦)) | 
| 139 |  | oveq2 7440 | . . . . . . . . . . . . . . . 16
⊢ (𝑥𝑂 = 𝑣 → (𝑦 ·s 𝑥𝑂) = (𝑦 ·s 𝑣)) | 
| 140 | 138, 139 | eqeq12d 2752 | . . . . . . . . . . . . . . 15
⊢ (𝑥𝑂 = 𝑣 → ((𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂) ↔ (𝑣 ·s 𝑦) = (𝑦 ·s 𝑣))) | 
| 141 |  | simplr2 1216 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))(𝑥𝑂 ·s
𝑦) = (𝑦 ·s 𝑥𝑂)) | 
| 142 |  | simprl 770 | . . . . . . . . . . . . . . . 16
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑣 ∈ ( R ‘𝑥)) | 
| 143 |  | elun2 4182 | . . . . . . . . . . . . . . . 16
⊢ (𝑣 ∈ ( R ‘𝑥) → 𝑣 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 144 | 142, 143 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑣 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))) | 
| 145 | 140, 141,
144 | rspcdva 3622 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑣 ·s 𝑦) = (𝑦 ·s 𝑣)) | 
| 146 |  | oveq2 7440 | . . . . . . . . . . . . . . . 16
⊢ (𝑦𝑂 = 𝑤 → (𝑥 ·s 𝑦𝑂) = (𝑥 ·s 𝑤)) | 
| 147 |  | oveq1 7439 | . . . . . . . . . . . . . . . 16
⊢ (𝑦𝑂 = 𝑤 → (𝑦𝑂 ·s
𝑥) = (𝑤 ·s 𝑥)) | 
| 148 | 146, 147 | eqeq12d 2752 | . . . . . . . . . . . . . . 15
⊢ (𝑦𝑂 = 𝑤 → ((𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥) ↔ (𝑥 ·s 𝑤) = (𝑤 ·s 𝑥))) | 
| 149 |  | simplr3 1217 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥)) | 
| 150 |  | simprr 772 | . . . . . . . . . . . . . . . 16
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑤 ∈ ( L ‘𝑦)) | 
| 151 |  | elun1 4181 | . . . . . . . . . . . . . . . 16
⊢ (𝑤 ∈ ( L ‘𝑦) → 𝑤 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 152 | 150, 151 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑤 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))) | 
| 153 | 148, 149,
152 | rspcdva 3622 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑥 ·s 𝑤) = (𝑤 ·s 𝑥)) | 
| 154 | 145, 153 | oveq12d 7450 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) = ((𝑦 ·s 𝑣) +s (𝑤 ·s 𝑥))) | 
| 155 |  | simpllr 775 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑦 ∈  No
) | 
| 156 | 75, 142 | sselid 3980 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑣 ∈  No
) | 
| 157 | 155, 156 | mulscld 28162 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑦 ·s 𝑣) ∈  No
) | 
| 158 | 37, 150 | sselid 3980 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑤 ∈  No
) | 
| 159 |  | simplll 774 | . . . . . . . . . . . . . . 15
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → 𝑥 ∈  No
) | 
| 160 | 158, 159 | mulscld 28162 | . . . . . . . . . . . . . 14
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑤 ·s 𝑥) ∈  No
) | 
| 161 | 157, 160 | addscomd 28001 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ((𝑦 ·s 𝑣) +s (𝑤 ·s 𝑥)) = ((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣))) | 
| 162 | 154, 161 | eqtrd 2776 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) = ((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣))) | 
| 163 |  | oveq1 7439 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑣 → (𝑥𝑂 ·s
𝑦𝑂) =
(𝑣 ·s
𝑦𝑂)) | 
| 164 |  | oveq2 7440 | . . . . . . . . . . . . . 14
⊢ (𝑥𝑂 = 𝑣 → (𝑦𝑂 ·s
𝑥𝑂) =
(𝑦𝑂
·s 𝑣)) | 
| 165 | 163, 164 | eqeq12d 2752 | . . . . . . . . . . . . 13
⊢ (𝑥𝑂 = 𝑣 → ((𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ↔ (𝑣 ·s 𝑦𝑂) = (𝑦𝑂
·s 𝑣))) | 
| 166 |  | oveq2 7440 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑤 → (𝑣 ·s 𝑦𝑂) = (𝑣 ·s 𝑤)) | 
| 167 |  | oveq1 7439 | . . . . . . . . . . . . . 14
⊢ (𝑦𝑂 = 𝑤 → (𝑦𝑂 ·s
𝑣) = (𝑤 ·s 𝑣)) | 
| 168 | 166, 167 | eqeq12d 2752 | . . . . . . . . . . . . 13
⊢ (𝑦𝑂 = 𝑤 → ((𝑣 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑣) ↔ (𝑣 ·s 𝑤) = (𝑤 ·s 𝑣))) | 
| 169 |  | simplr1 1215 | . . . . . . . . . . . . 13
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → ∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂)) | 
| 170 | 165, 168,
169, 144, 152 | rspc2dv 3636 | . . . . . . . . . . . 12
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑣 ·s 𝑤) = (𝑤 ·s 𝑣)) | 
| 171 | 162, 170 | oveq12d 7450 | . . . . . . . . . . 11
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤)) = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))) | 
| 172 | 171 | eqeq2d 2747 | . . . . . . . . . 10
⊢ ((((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) ∧ (𝑣 ∈ ( R ‘𝑥) ∧ 𝑤 ∈ ( L ‘𝑦))) → (𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤)) ↔ 𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣)))) | 
| 173 | 172 | 2rexbidva 3219 | . . . . . . . . 9
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤)) ↔ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣)))) | 
| 174 |  | rexcom 3289 | . . . . . . . . 9
⊢
(∃𝑣 ∈ ( R
‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣)) ↔ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))) | 
| 175 | 173, 174 | bitrdi 287 | . . . . . . . 8
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤)) ↔ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣)))) | 
| 176 | 175 | abbidv 2807 | . . . . . . 7
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))} = {𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))}) | 
| 177 | 137, 176 | uneq12d 4168 | . . . . . 6
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → ({𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} ∪ {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))}) = ({𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))} ∪ {𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))})) | 
| 178 |  | uncom 4157 | . . . . . 6
⊢ ({𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))} ∪ {𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))}) = ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}) | 
| 179 | 177, 178 | eqtrdi 2792 | . . . . 5
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → ({𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} ∪ {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))}) = ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))})) | 
| 180 | 98, 179 | oveq12d 7450 | . . . 4
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (({𝑎 ∣ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞))} ∪ {𝑏 ∣ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠))}) |s ({𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} ∪ {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))})) = (({𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))} ∪ {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))}) |s ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}))) | 
| 181 |  | mulsval 28136 | . . . . 5
⊢ ((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) → (𝑥 ·s 𝑦) = (({𝑎 ∣ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞))} ∪ {𝑏 ∣ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠))}) |s ({𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} ∪ {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))}))) | 
| 182 | 181 | adantr 480 | . . . 4
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (𝑥 ·s 𝑦) = (({𝑎 ∣ ∃𝑝 ∈ ( L ‘𝑥)∃𝑞 ∈ ( L ‘𝑦)𝑎 = (((𝑝 ·s 𝑦) +s (𝑥 ·s 𝑞)) -s (𝑝 ·s 𝑞))} ∪ {𝑏 ∣ ∃𝑟 ∈ ( R ‘𝑥)∃𝑠 ∈ ( R ‘𝑦)𝑏 = (((𝑟 ·s 𝑦) +s (𝑥 ·s 𝑠)) -s (𝑟 ·s 𝑠))}) |s ({𝑐 ∣ ∃𝑡 ∈ ( L ‘𝑥)∃𝑢 ∈ ( R ‘𝑦)𝑐 = (((𝑡 ·s 𝑦) +s (𝑥 ·s 𝑢)) -s (𝑡 ·s 𝑢))} ∪ {𝑑 ∣ ∃𝑣 ∈ ( R ‘𝑥)∃𝑤 ∈ ( L ‘𝑦)𝑑 = (((𝑣 ·s 𝑦) +s (𝑥 ·s 𝑤)) -s (𝑣 ·s 𝑤))}))) | 
| 183 |  | mulsval 28136 | . . . . . 6
⊢ ((𝑦 ∈ 
No  ∧ 𝑥 ∈
 No ) → (𝑦 ·s 𝑥) = (({𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))} ∪ {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))}) |s ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}))) | 
| 184 | 183 | ancoms 458 | . . . . 5
⊢ ((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) → (𝑦 ·s 𝑥) = (({𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))} ∪ {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))}) |s ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}))) | 
| 185 | 184 | adantr 480 | . . . 4
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (𝑦 ·s 𝑥) = (({𝑎 ∣ ∃𝑞 ∈ ( L ‘𝑦)∃𝑝 ∈ ( L ‘𝑥)𝑎 = (((𝑞 ·s 𝑥) +s (𝑦 ·s 𝑝)) -s (𝑞 ·s 𝑝))} ∪ {𝑏 ∣ ∃𝑠 ∈ ( R ‘𝑦)∃𝑟 ∈ ( R ‘𝑥)𝑏 = (((𝑠 ·s 𝑥) +s (𝑦 ·s 𝑟)) -s (𝑠 ·s 𝑟))}) |s ({𝑑 ∣ ∃𝑤 ∈ ( L ‘𝑦)∃𝑣 ∈ ( R ‘𝑥)𝑑 = (((𝑤 ·s 𝑥) +s (𝑦 ·s 𝑣)) -s (𝑤 ·s 𝑣))} ∪ {𝑐 ∣ ∃𝑢 ∈ ( R ‘𝑦)∃𝑡 ∈ ( L ‘𝑥)𝑐 = (((𝑢 ·s 𝑥) +s (𝑦 ·s 𝑡)) -s (𝑢 ·s 𝑡))}))) | 
| 186 | 180, 182,
185 | 3eqtr4d 2786 | . . 3
⊢ (((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) ∧ (∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥))) → (𝑥 ·s 𝑦) = (𝑦 ·s 𝑥)) | 
| 187 | 186 | ex 412 | . 2
⊢ ((𝑥 ∈ 
No  ∧ 𝑦 ∈
 No ) → ((∀𝑥𝑂 ∈ (( L ‘𝑥) ∪ ( R ‘𝑥))∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥𝑂 ·s
𝑦𝑂) =
(𝑦𝑂
·s 𝑥𝑂) ∧ ∀𝑥𝑂 ∈ (( L
‘𝑥) ∪ ( R
‘𝑥))(𝑥𝑂
·s 𝑦) =
(𝑦 ·s
𝑥𝑂)
∧ ∀𝑦𝑂 ∈ (( L ‘𝑦) ∪ ( R ‘𝑦))(𝑥 ·s 𝑦𝑂) = (𝑦𝑂 ·s
𝑥)) → (𝑥 ·s 𝑦) = (𝑦 ·s 𝑥))) | 
| 188 | 3, 6, 9, 12, 15, 187 | no2inds 27989 | 1
⊢ ((𝐴 ∈ 
No  ∧ 𝐵 ∈
 No ) → (𝐴 ·s 𝐵) = (𝐵 ·s 𝐴)) |