| Step | Hyp | Ref
| Expression |
| 1 | | df-scut 27829 |
. . . 4
⊢ |s =
(𝑎 ∈ 𝒫 No , 𝑏 ∈ ( <<s “ {𝑎}) ↦ (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)}))) |
| 2 | 1 | mpofun 7558 |
. . 3
⊢ Fun
|s |
| 3 | | dmscut 27857 |
. . 3
⊢ dom |s =
<<s |
| 4 | | df-fn 6563 |
. . 3
⊢ ( |s Fn
<<s ↔ (Fun |s ∧ dom |s = <<s )) |
| 5 | 2, 3, 4 | mpbir2an 711 |
. 2
⊢ |s Fn
<<s |
| 6 | 1 | rnmpo 7567 |
. . 3
⊢ ran |s =
{𝑧 ∣ ∃𝑎 ∈ 𝒫 No ∃𝑏 ∈ ( <<s “ {𝑎})𝑧 = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)}))} |
| 7 | | vex 3483 |
. . . . . . . . . 10
⊢ 𝑎 ∈ V |
| 8 | | vex 3483 |
. . . . . . . . . 10
⊢ 𝑏 ∈ V |
| 9 | 7, 8 | elimasn 6107 |
. . . . . . . . 9
⊢ (𝑏 ∈ ( <<s “
{𝑎}) ↔ 〈𝑎, 𝑏〉 ∈ <<s ) |
| 10 | | df-br 5143 |
. . . . . . . . 9
⊢ (𝑎 <<s 𝑏 ↔ 〈𝑎, 𝑏〉 ∈ <<s ) |
| 11 | 9, 10 | bitr4i 278 |
. . . . . . . 8
⊢ (𝑏 ∈ ( <<s “
{𝑎}) ↔ 𝑎 <<s 𝑏) |
| 12 | | scutval 27846 |
. . . . . . . . 9
⊢ (𝑎 <<s 𝑏 → (𝑎 |s 𝑏) = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)}))) |
| 13 | | scutcl 27848 |
. . . . . . . . 9
⊢ (𝑎 <<s 𝑏 → (𝑎 |s 𝑏) ∈ No
) |
| 14 | 12, 13 | eqeltrrd 2841 |
. . . . . . . 8
⊢ (𝑎 <<s 𝑏 → (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) ∈ No
) |
| 15 | 11, 14 | sylbi 217 |
. . . . . . 7
⊢ (𝑏 ∈ ( <<s “
{𝑎}) →
(℩𝑥 ∈
{𝑦 ∈ No ∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) ∈ No
) |
| 16 | | eleq1a 2835 |
. . . . . . 7
⊢
((℩𝑥
∈ {𝑦 ∈ No ∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) ∈ No
→ (𝑧 =
(℩𝑥 ∈
{𝑦 ∈ No ∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) → 𝑧 ∈ No
)) |
| 17 | 15, 16 | syl 17 |
. . . . . 6
⊢ (𝑏 ∈ ( <<s “
{𝑎}) → (𝑧 = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) → 𝑧 ∈ No
)) |
| 18 | 17 | adantl 481 |
. . . . 5
⊢ ((𝑎 ∈ 𝒫 No ∧ 𝑏 ∈ ( <<s “ {𝑎})) → (𝑧 = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) → 𝑧 ∈ No
)) |
| 19 | 18 | rexlimivv 3200 |
. . . 4
⊢
(∃𝑎 ∈
𝒫 No ∃𝑏 ∈ ( <<s “ {𝑎})𝑧 = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)})) → 𝑧 ∈ No
) |
| 20 | 19 | abssi 4069 |
. . 3
⊢ {𝑧 ∣ ∃𝑎 ∈ 𝒫 No ∃𝑏 ∈ ( <<s “ {𝑎})𝑧 = (℩𝑥 ∈ {𝑦 ∈ No
∣ (𝑎 <<s {𝑦} ∧ {𝑦} <<s 𝑏)} ( bday
‘𝑥) = ∩ ( bday “ {𝑦 ∈
No ∣ (𝑎
<<s {𝑦} ∧ {𝑦} <<s 𝑏)}))} ⊆ No
|
| 21 | 6, 20 | eqsstri 4029 |
. 2
⊢ ran |s
⊆ No |
| 22 | | df-f 6564 |
. 2
⊢ ( |s :
<<s ⟶ No ↔ ( |s Fn <<s
∧ ran |s ⊆ No )) |
| 23 | 5, 21, 22 | mpbir2an 711 |
1
⊢ |s :
<<s ⟶ No |