Step |
Hyp |
Ref |
Expression |
1 |
|
psrbag0.d |
⊢ 𝐷 = { 𝑓 ∈ ( ℕ0 ↑m 𝐼 ) ∣ ( ◡ 𝑓 “ ℕ ) ∈ Fin } |
2 |
|
0nn0 |
⊢ 0 ∈ ℕ0 |
3 |
2
|
fconst6 |
⊢ ( 𝐼 × { 0 } ) : 𝐼 ⟶ ℕ0 |
4 |
|
c0ex |
⊢ 0 ∈ V |
5 |
4
|
fconst |
⊢ ( 𝐼 × { 0 } ) : 𝐼 ⟶ { 0 } |
6 |
|
incom |
⊢ ( { 0 } ∩ ℕ ) = ( ℕ ∩ { 0 } ) |
7 |
|
0nnn |
⊢ ¬ 0 ∈ ℕ |
8 |
|
disjsn |
⊢ ( ( ℕ ∩ { 0 } ) = ∅ ↔ ¬ 0 ∈ ℕ ) |
9 |
7 8
|
mpbir |
⊢ ( ℕ ∩ { 0 } ) = ∅ |
10 |
6 9
|
eqtri |
⊢ ( { 0 } ∩ ℕ ) = ∅ |
11 |
|
fimacnvdisj |
⊢ ( ( ( 𝐼 × { 0 } ) : 𝐼 ⟶ { 0 } ∧ ( { 0 } ∩ ℕ ) = ∅ ) → ( ◡ ( 𝐼 × { 0 } ) “ ℕ ) = ∅ ) |
12 |
5 10 11
|
mp2an |
⊢ ( ◡ ( 𝐼 × { 0 } ) “ ℕ ) = ∅ |
13 |
|
0fin |
⊢ ∅ ∈ Fin |
14 |
12 13
|
eqeltri |
⊢ ( ◡ ( 𝐼 × { 0 } ) “ ℕ ) ∈ Fin |
15 |
3 14
|
pm3.2i |
⊢ ( ( 𝐼 × { 0 } ) : 𝐼 ⟶ ℕ0 ∧ ( ◡ ( 𝐼 × { 0 } ) “ ℕ ) ∈ Fin ) |
16 |
1
|
psrbag |
⊢ ( 𝐼 ∈ 𝑉 → ( ( 𝐼 × { 0 } ) ∈ 𝐷 ↔ ( ( 𝐼 × { 0 } ) : 𝐼 ⟶ ℕ0 ∧ ( ◡ ( 𝐼 × { 0 } ) “ ℕ ) ∈ Fin ) ) ) |
17 |
15 16
|
mpbiri |
⊢ ( 𝐼 ∈ 𝑉 → ( 𝐼 × { 0 } ) ∈ 𝐷 ) |