| Step | Hyp | Ref
 | Expression | 
| 1 |   | dmoprab 6003 | 
. . 3
⊢ dom
{〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ Q ∧ 𝑦 ∈ Q) ∧
∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q ))} =
{〈𝑥, 𝑦〉 ∣ ∃𝑧((𝑥 ∈ Q ∧ 𝑦 ∈ Q) ∧
∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))} | 
| 2 |   | df-plqqs 7416 | 
. . . 4
⊢ 
+Q = {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ Q ∧ 𝑦 ∈ Q) ∧
∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))} | 
| 3 | 2 | dmeqi 4867 | 
. . 3
⊢ dom
+Q = dom {〈〈𝑥, 𝑦〉, 𝑧〉 ∣ ((𝑥 ∈ Q ∧ 𝑦 ∈ Q) ∧
∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))} | 
| 4 |   | dmaddpqlem 7444 | 
. . . . . . . . 9
⊢ (𝑥 ∈ Q →
∃𝑤∃𝑣 𝑥 = [〈𝑤, 𝑣〉] ~Q
) | 
| 5 |   | dmaddpqlem 7444 | 
. . . . . . . . 9
⊢ (𝑦 ∈ Q →
∃𝑢∃𝑓 𝑦 = [〈𝑢, 𝑓〉] ~Q
) | 
| 6 | 4, 5 | anim12i 338 | 
. . . . . . . 8
⊢ ((𝑥 ∈ Q ∧
𝑦 ∈ Q)
→ (∃𝑤∃𝑣 𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
∃𝑢∃𝑓 𝑦 = [〈𝑢, 𝑓〉] ~Q
)) | 
| 7 |   | ee4anv 1953 | 
. . . . . . . 8
⊢
(∃𝑤∃𝑣∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ↔
(∃𝑤∃𝑣 𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
∃𝑢∃𝑓 𝑦 = [〈𝑢, 𝑓〉] ~Q
)) | 
| 8 | 6, 7 | sylibr 134 | 
. . . . . . 7
⊢ ((𝑥 ∈ Q ∧
𝑦 ∈ Q)
→ ∃𝑤∃𝑣∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q
)) | 
| 9 |   | enqex 7427 | 
. . . . . . . . . . . . . 14
⊢ 
~Q ∈ V | 
| 10 |   | ecexg 6596 | 
. . . . . . . . . . . . . 14
⊢ (
~Q ∈ V → [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q ∈
V) | 
| 11 | 9, 10 | ax-mp 5 | 
. . . . . . . . . . . . 13
⊢
[(〈𝑤, 𝑣〉
+pQ 〈𝑢, 𝑓〉)] ~Q ∈
V | 
| 12 | 11 | isseti 2771 | 
. . . . . . . . . . . 12
⊢
∃𝑧 𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)]
~Q | 
| 13 |   | ax-ia3 108 | 
. . . . . . . . . . . . 13
⊢ ((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
(𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q →
((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))) | 
| 14 | 13 | eximdv 1894 | 
. . . . . . . . . . . 12
⊢ ((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
(∃𝑧 𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q →
∃𝑧((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))) | 
| 15 | 12, 14 | mpi 15 | 
. . . . . . . . . . 11
⊢ ((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
∃𝑧((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 16 | 15 | 2eximi 1615 | 
. . . . . . . . . 10
⊢
(∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
∃𝑢∃𝑓∃𝑧((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 17 |   | exrot3 1704 | 
. . . . . . . . . 10
⊢
(∃𝑧∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q ) ↔
∃𝑢∃𝑓∃𝑧((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 18 | 16, 17 | sylibr 134 | 
. . . . . . . . 9
⊢
(∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
∃𝑧∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 19 | 18 | 2eximi 1615 | 
. . . . . . . 8
⊢
(∃𝑤∃𝑣∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
∃𝑤∃𝑣∃𝑧∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 20 |   | exrot3 1704 | 
. . . . . . . 8
⊢
(∃𝑧∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q ) ↔
∃𝑤∃𝑣∃𝑧∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 21 | 19, 20 | sylibr 134 | 
. . . . . . 7
⊢
(∃𝑤∃𝑣∃𝑢∃𝑓(𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) →
∃𝑧∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 22 | 8, 21 | syl 14 | 
. . . . . 6
⊢ ((𝑥 ∈ Q ∧
𝑦 ∈ Q)
→ ∃𝑧∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
)) | 
| 23 | 22 | pm4.71i 391 | 
. . . . 5
⊢ ((𝑥 ∈ Q ∧
𝑦 ∈ Q)
↔ ((𝑥 ∈
Q ∧ 𝑦
∈ Q) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))) | 
| 24 |   | 19.42v 1921 | 
. . . . 5
⊢
(∃𝑧((𝑥 ∈ Q ∧
𝑦 ∈ Q)
∧ ∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q ))
↔ ((𝑥 ∈
Q ∧ 𝑦
∈ Q) ∧ ∃𝑧∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))) | 
| 25 | 23, 24 | bitr4i 187 | 
. . . 4
⊢ ((𝑥 ∈ Q ∧
𝑦 ∈ Q)
↔ ∃𝑧((𝑥 ∈ Q ∧
𝑦 ∈ Q)
∧ ∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))) | 
| 26 | 25 | opabbii 4100 | 
. . 3
⊢
{〈𝑥, 𝑦〉 ∣ (𝑥 ∈ Q ∧
𝑦 ∈ Q)}
= {〈𝑥, 𝑦〉 ∣ ∃𝑧((𝑥 ∈ Q ∧ 𝑦 ∈ Q) ∧
∃𝑤∃𝑣∃𝑢∃𝑓((𝑥 = [〈𝑤, 𝑣〉] ~Q ∧
𝑦 = [〈𝑢, 𝑓〉] ~Q ) ∧
𝑧 = [(〈𝑤, 𝑣〉 +pQ
〈𝑢, 𝑓〉)] ~Q
))} | 
| 27 | 1, 3, 26 | 3eqtr4i 2227 | 
. 2
⊢ dom
+Q = {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ Q ∧ 𝑦 ∈
Q)} | 
| 28 |   | df-xp 4669 | 
. 2
⊢
(Q × Q) = {〈𝑥, 𝑦〉 ∣ (𝑥 ∈ Q ∧ 𝑦 ∈
Q)} | 
| 29 | 27, 28 | eqtr4i 2220 | 
1
⊢ dom
+Q = (Q ×
Q) |