Step |
Hyp |
Ref |
Expression |
1 |
|
madebday |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( 𝑋 ∈ ( M ‘ 𝐴 ) ↔ ( bday ‘ 𝑋 ) ⊆ 𝐴 ) ) |
2 |
|
oldbday |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( 𝑋 ∈ ( O ‘ 𝐴 ) ↔ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) |
3 |
2
|
notbid |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( ¬ 𝑋 ∈ ( O ‘ 𝐴 ) ↔ ¬ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) |
4 |
1 3
|
anbi12d |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( ( 𝑋 ∈ ( M ‘ 𝐴 ) ∧ ¬ 𝑋 ∈ ( O ‘ 𝐴 ) ) ↔ ( ( bday ‘ 𝑋 ) ⊆ 𝐴 ∧ ¬ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) ) |
5 |
|
newval |
⊢ ( 𝐴 ∈ On → ( N ‘ 𝐴 ) = ( ( M ‘ 𝐴 ) ∖ ( O ‘ 𝐴 ) ) ) |
6 |
5
|
eleq2d |
⊢ ( 𝐴 ∈ On → ( 𝑋 ∈ ( N ‘ 𝐴 ) ↔ 𝑋 ∈ ( ( M ‘ 𝐴 ) ∖ ( O ‘ 𝐴 ) ) ) ) |
7 |
|
eldif |
⊢ ( 𝑋 ∈ ( ( M ‘ 𝐴 ) ∖ ( O ‘ 𝐴 ) ) ↔ ( 𝑋 ∈ ( M ‘ 𝐴 ) ∧ ¬ 𝑋 ∈ ( O ‘ 𝐴 ) ) ) |
8 |
6 7
|
bitrdi |
⊢ ( 𝐴 ∈ On → ( 𝑋 ∈ ( N ‘ 𝐴 ) ↔ ( 𝑋 ∈ ( M ‘ 𝐴 ) ∧ ¬ 𝑋 ∈ ( O ‘ 𝐴 ) ) ) ) |
9 |
8
|
adantr |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( 𝑋 ∈ ( N ‘ 𝐴 ) ↔ ( 𝑋 ∈ ( M ‘ 𝐴 ) ∧ ¬ 𝑋 ∈ ( O ‘ 𝐴 ) ) ) ) |
10 |
|
bdayelon |
⊢ ( bday ‘ 𝑋 ) ∈ On |
11 |
10
|
onordi |
⊢ Ord ( bday ‘ 𝑋 ) |
12 |
|
eloni |
⊢ ( 𝐴 ∈ On → Ord 𝐴 ) |
13 |
|
ordtri4 |
⊢ ( ( Ord ( bday ‘ 𝑋 ) ∧ Ord 𝐴 ) → ( ( bday ‘ 𝑋 ) = 𝐴 ↔ ( ( bday ‘ 𝑋 ) ⊆ 𝐴 ∧ ¬ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) ) |
14 |
11 12 13
|
sylancr |
⊢ ( 𝐴 ∈ On → ( ( bday ‘ 𝑋 ) = 𝐴 ↔ ( ( bday ‘ 𝑋 ) ⊆ 𝐴 ∧ ¬ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) ) |
15 |
14
|
adantr |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( ( bday ‘ 𝑋 ) = 𝐴 ↔ ( ( bday ‘ 𝑋 ) ⊆ 𝐴 ∧ ¬ ( bday ‘ 𝑋 ) ∈ 𝐴 ) ) ) |
16 |
4 9 15
|
3bitr4d |
⊢ ( ( 𝐴 ∈ On ∧ 𝑋 ∈ No ) → ( 𝑋 ∈ ( N ‘ 𝐴 ) ↔ ( bday ‘ 𝑋 ) = 𝐴 ) ) |