| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | addsval 27995 | . 2
⊢ ((𝐴 ∈ 
No  ∧ 𝐵 ∈
 No ) → (𝐴 +s 𝐵) = (({𝑎 ∣ ∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏)}) |s ({𝑎 ∣ ∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑)}))) | 
| 2 |  | eqeq1 2741 | . . . . . . 7
⊢ (𝑎 = 𝑦 → (𝑎 = (𝑏 +s 𝐵) ↔ 𝑦 = (𝑏 +s 𝐵))) | 
| 3 | 2 | rexbidv 3179 | . . . . . 6
⊢ (𝑎 = 𝑦 → (∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵) ↔ ∃𝑏 ∈ ( L ‘𝐴)𝑦 = (𝑏 +s 𝐵))) | 
| 4 |  | oveq1 7438 | . . . . . . . 8
⊢ (𝑏 = 𝑙 → (𝑏 +s 𝐵) = (𝑙 +s 𝐵)) | 
| 5 | 4 | eqeq2d 2748 | . . . . . . 7
⊢ (𝑏 = 𝑙 → (𝑦 = (𝑏 +s 𝐵) ↔ 𝑦 = (𝑙 +s 𝐵))) | 
| 6 | 5 | cbvrexvw 3238 | . . . . . 6
⊢
(∃𝑏 ∈ ( L
‘𝐴)𝑦 = (𝑏 +s 𝐵) ↔ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵)) | 
| 7 | 3, 6 | bitrdi 287 | . . . . 5
⊢ (𝑎 = 𝑦 → (∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵) ↔ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵))) | 
| 8 | 7 | cbvabv 2812 | . . . 4
⊢ {𝑎 ∣ ∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵)} = {𝑦 ∣ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵)} | 
| 9 |  | eqeq1 2741 | . . . . . . 7
⊢ (𝑐 = 𝑧 → (𝑐 = (𝐴 +s 𝑏) ↔ 𝑧 = (𝐴 +s 𝑏))) | 
| 10 | 9 | rexbidv 3179 | . . . . . 6
⊢ (𝑐 = 𝑧 → (∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏) ↔ ∃𝑏 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑏))) | 
| 11 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑏 = 𝑚 → (𝐴 +s 𝑏) = (𝐴 +s 𝑚)) | 
| 12 | 11 | eqeq2d 2748 | . . . . . . 7
⊢ (𝑏 = 𝑚 → (𝑧 = (𝐴 +s 𝑏) ↔ 𝑧 = (𝐴 +s 𝑚))) | 
| 13 | 12 | cbvrexvw 3238 | . . . . . 6
⊢
(∃𝑏 ∈ ( L
‘𝐵)𝑧 = (𝐴 +s 𝑏) ↔ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚)) | 
| 14 | 10, 13 | bitrdi 287 | . . . . 5
⊢ (𝑐 = 𝑧 → (∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏) ↔ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚))) | 
| 15 | 14 | cbvabv 2812 | . . . 4
⊢ {𝑐 ∣ ∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏)} = {𝑧 ∣ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚)} | 
| 16 | 8, 15 | uneq12i 4166 | . . 3
⊢ ({𝑎 ∣ ∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏)}) = ({𝑦 ∣ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵)} ∪ {𝑧 ∣ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚)}) | 
| 17 |  | eqeq1 2741 | . . . . . . 7
⊢ (𝑎 = 𝑤 → (𝑎 = (𝑑 +s 𝐵) ↔ 𝑤 = (𝑑 +s 𝐵))) | 
| 18 | 17 | rexbidv 3179 | . . . . . 6
⊢ (𝑎 = 𝑤 → (∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵) ↔ ∃𝑑 ∈ ( R ‘𝐴)𝑤 = (𝑑 +s 𝐵))) | 
| 19 |  | oveq1 7438 | . . . . . . . 8
⊢ (𝑑 = 𝑟 → (𝑑 +s 𝐵) = (𝑟 +s 𝐵)) | 
| 20 | 19 | eqeq2d 2748 | . . . . . . 7
⊢ (𝑑 = 𝑟 → (𝑤 = (𝑑 +s 𝐵) ↔ 𝑤 = (𝑟 +s 𝐵))) | 
| 21 | 20 | cbvrexvw 3238 | . . . . . 6
⊢
(∃𝑑 ∈ ( R
‘𝐴)𝑤 = (𝑑 +s 𝐵) ↔ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵)) | 
| 22 | 18, 21 | bitrdi 287 | . . . . 5
⊢ (𝑎 = 𝑤 → (∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵) ↔ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵))) | 
| 23 | 22 | cbvabv 2812 | . . . 4
⊢ {𝑎 ∣ ∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵)} = {𝑤 ∣ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵)} | 
| 24 |  | eqeq1 2741 | . . . . . . 7
⊢ (𝑐 = 𝑡 → (𝑐 = (𝐴 +s 𝑑) ↔ 𝑡 = (𝐴 +s 𝑑))) | 
| 25 | 24 | rexbidv 3179 | . . . . . 6
⊢ (𝑐 = 𝑡 → (∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑) ↔ ∃𝑑 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑑))) | 
| 26 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑑 = 𝑠 → (𝐴 +s 𝑑) = (𝐴 +s 𝑠)) | 
| 27 | 26 | eqeq2d 2748 | . . . . . . 7
⊢ (𝑑 = 𝑠 → (𝑡 = (𝐴 +s 𝑑) ↔ 𝑡 = (𝐴 +s 𝑠))) | 
| 28 | 27 | cbvrexvw 3238 | . . . . . 6
⊢
(∃𝑑 ∈ ( R
‘𝐵)𝑡 = (𝐴 +s 𝑑) ↔ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠)) | 
| 29 | 25, 28 | bitrdi 287 | . . . . 5
⊢ (𝑐 = 𝑡 → (∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑) ↔ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠))) | 
| 30 | 29 | cbvabv 2812 | . . . 4
⊢ {𝑐 ∣ ∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑)} = {𝑡 ∣ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠)} | 
| 31 | 23, 30 | uneq12i 4166 | . . 3
⊢ ({𝑎 ∣ ∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑)}) = ({𝑤 ∣ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵)} ∪ {𝑡 ∣ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠)}) | 
| 32 | 16, 31 | oveq12i 7443 | . 2
⊢ (({𝑎 ∣ ∃𝑏 ∈ ( L ‘𝐴)𝑎 = (𝑏 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑏 ∈ ( L ‘𝐵)𝑐 = (𝐴 +s 𝑏)}) |s ({𝑎 ∣ ∃𝑑 ∈ ( R ‘𝐴)𝑎 = (𝑑 +s 𝐵)} ∪ {𝑐 ∣ ∃𝑑 ∈ ( R ‘𝐵)𝑐 = (𝐴 +s 𝑑)})) = (({𝑦 ∣ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵)} ∪ {𝑧 ∣ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚)}) |s ({𝑤 ∣ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵)} ∪ {𝑡 ∣ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠)})) | 
| 33 | 1, 32 | eqtrdi 2793 | 1
⊢ ((𝐴 ∈ 
No  ∧ 𝐵 ∈
 No ) → (𝐴 +s 𝐵) = (({𝑦 ∣ ∃𝑙 ∈ ( L ‘𝐴)𝑦 = (𝑙 +s 𝐵)} ∪ {𝑧 ∣ ∃𝑚 ∈ ( L ‘𝐵)𝑧 = (𝐴 +s 𝑚)}) |s ({𝑤 ∣ ∃𝑟 ∈ ( R ‘𝐴)𝑤 = (𝑟 +s 𝐵)} ∪ {𝑡 ∣ ∃𝑠 ∈ ( R ‘𝐵)𝑡 = (𝐴 +s 𝑠)}))) |