Step |
Hyp |
Ref |
Expression |
1 |
|
pointset.a |
⊢ 𝐴 = ( Atoms ‘ 𝐾 ) |
2 |
|
pointset.p |
⊢ 𝑃 = ( Points ‘ 𝐾 ) |
3 |
|
elex |
⊢ ( 𝐾 ∈ 𝐵 → 𝐾 ∈ V ) |
4 |
|
fveq2 |
⊢ ( 𝑘 = 𝐾 → ( Atoms ‘ 𝑘 ) = ( Atoms ‘ 𝐾 ) ) |
5 |
4 1
|
eqtr4di |
⊢ ( 𝑘 = 𝐾 → ( Atoms ‘ 𝑘 ) = 𝐴 ) |
6 |
5
|
rexeqdv |
⊢ ( 𝑘 = 𝐾 → ( ∃ 𝑎 ∈ ( Atoms ‘ 𝑘 ) 𝑝 = { 𝑎 } ↔ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } ) ) |
7 |
6
|
abbidv |
⊢ ( 𝑘 = 𝐾 → { 𝑝 ∣ ∃ 𝑎 ∈ ( Atoms ‘ 𝑘 ) 𝑝 = { 𝑎 } } = { 𝑝 ∣ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } } ) |
8 |
|
df-pointsN |
⊢ Points = ( 𝑘 ∈ V ↦ { 𝑝 ∣ ∃ 𝑎 ∈ ( Atoms ‘ 𝑘 ) 𝑝 = { 𝑎 } } ) |
9 |
1
|
fvexi |
⊢ 𝐴 ∈ V |
10 |
9
|
abrexex |
⊢ { 𝑝 ∣ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } } ∈ V |
11 |
7 8 10
|
fvmpt |
⊢ ( 𝐾 ∈ V → ( Points ‘ 𝐾 ) = { 𝑝 ∣ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } } ) |
12 |
2 11
|
syl5eq |
⊢ ( 𝐾 ∈ V → 𝑃 = { 𝑝 ∣ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } } ) |
13 |
3 12
|
syl |
⊢ ( 𝐾 ∈ 𝐵 → 𝑃 = { 𝑝 ∣ ∃ 𝑎 ∈ 𝐴 𝑝 = { 𝑎 } } ) |