Step |
Hyp |
Ref |
Expression |
1 |
|
mexval.k |
⊢ 𝐾 = ( mTC ‘ 𝑇 ) |
2 |
|
mexval.e |
⊢ 𝐸 = ( mEx ‘ 𝑇 ) |
3 |
|
mexval.r |
⊢ 𝑅 = ( mREx ‘ 𝑇 ) |
4 |
|
fveq2 |
⊢ ( 𝑡 = 𝑇 → ( mTC ‘ 𝑡 ) = ( mTC ‘ 𝑇 ) ) |
5 |
4 1
|
eqtr4di |
⊢ ( 𝑡 = 𝑇 → ( mTC ‘ 𝑡 ) = 𝐾 ) |
6 |
|
fveq2 |
⊢ ( 𝑡 = 𝑇 → ( mREx ‘ 𝑡 ) = ( mREx ‘ 𝑇 ) ) |
7 |
6 3
|
eqtr4di |
⊢ ( 𝑡 = 𝑇 → ( mREx ‘ 𝑡 ) = 𝑅 ) |
8 |
5 7
|
xpeq12d |
⊢ ( 𝑡 = 𝑇 → ( ( mTC ‘ 𝑡 ) × ( mREx ‘ 𝑡 ) ) = ( 𝐾 × 𝑅 ) ) |
9 |
|
df-mex |
⊢ mEx = ( 𝑡 ∈ V ↦ ( ( mTC ‘ 𝑡 ) × ( mREx ‘ 𝑡 ) ) ) |
10 |
|
fvex |
⊢ ( mTC ‘ 𝑡 ) ∈ V |
11 |
|
fvex |
⊢ ( mREx ‘ 𝑡 ) ∈ V |
12 |
10 11
|
xpex |
⊢ ( ( mTC ‘ 𝑡 ) × ( mREx ‘ 𝑡 ) ) ∈ V |
13 |
8 9 12
|
fvmpt3i |
⊢ ( 𝑇 ∈ V → ( mEx ‘ 𝑇 ) = ( 𝐾 × 𝑅 ) ) |
14 |
|
xp0 |
⊢ ( 𝐾 × ∅ ) = ∅ |
15 |
14
|
eqcomi |
⊢ ∅ = ( 𝐾 × ∅ ) |
16 |
|
fvprc |
⊢ ( ¬ 𝑇 ∈ V → ( mEx ‘ 𝑇 ) = ∅ ) |
17 |
|
fvprc |
⊢ ( ¬ 𝑇 ∈ V → ( mREx ‘ 𝑇 ) = ∅ ) |
18 |
3 17
|
syl5eq |
⊢ ( ¬ 𝑇 ∈ V → 𝑅 = ∅ ) |
19 |
18
|
xpeq2d |
⊢ ( ¬ 𝑇 ∈ V → ( 𝐾 × 𝑅 ) = ( 𝐾 × ∅ ) ) |
20 |
15 16 19
|
3eqtr4a |
⊢ ( ¬ 𝑇 ∈ V → ( mEx ‘ 𝑇 ) = ( 𝐾 × 𝑅 ) ) |
21 |
13 20
|
pm2.61i |
⊢ ( mEx ‘ 𝑇 ) = ( 𝐾 × 𝑅 ) |
22 |
2 21
|
eqtri |
⊢ 𝐸 = ( 𝐾 × 𝑅 ) |