Step |
Hyp |
Ref |
Expression |
1 |
|
fofn |
⊢ ( 𝐹 : 𝐴 –onto→ 𝐵 → 𝐹 Fn 𝐴 ) |
2 |
1
|
3ad2ant3 |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → 𝐹 Fn 𝐴 ) |
3 |
|
forn |
⊢ ( 𝐹 : 𝐴 –onto→ 𝐵 → ran 𝐹 = 𝐵 ) |
4 |
|
eqimss2 |
⊢ ( ran 𝐹 = 𝐵 → 𝐵 ⊆ ran 𝐹 ) |
5 |
3 4
|
syl |
⊢ ( 𝐹 : 𝐴 –onto→ 𝐵 → 𝐵 ⊆ ran 𝐹 ) |
6 |
5
|
3ad2ant3 |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → 𝐵 ⊆ ran 𝐹 ) |
7 |
|
simp2 |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → 𝐵 ∈ Fin ) |
8 |
|
fipreima |
⊢ ( ( 𝐹 Fn 𝐴 ∧ 𝐵 ⊆ ran 𝐹 ∧ 𝐵 ∈ Fin ) → ∃ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ( 𝐹 “ 𝑥 ) = 𝐵 ) |
9 |
2 6 7 8
|
syl3anc |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → ∃ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ( 𝐹 “ 𝑥 ) = 𝐵 ) |
10 |
|
elinel2 |
⊢ ( 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) → 𝑥 ∈ Fin ) |
11 |
10
|
adantl |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝑥 ∈ Fin ) |
12 |
|
finnum |
⊢ ( 𝑥 ∈ Fin → 𝑥 ∈ dom card ) |
13 |
11 12
|
syl |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝑥 ∈ dom card ) |
14 |
|
simpl3 |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝐹 : 𝐴 –onto→ 𝐵 ) |
15 |
|
fofun |
⊢ ( 𝐹 : 𝐴 –onto→ 𝐵 → Fun 𝐹 ) |
16 |
14 15
|
syl |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → Fun 𝐹 ) |
17 |
|
elinel1 |
⊢ ( 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) → 𝑥 ∈ 𝒫 𝐴 ) |
18 |
17
|
elpwid |
⊢ ( 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) → 𝑥 ⊆ 𝐴 ) |
19 |
18
|
adantl |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝑥 ⊆ 𝐴 ) |
20 |
|
fof |
⊢ ( 𝐹 : 𝐴 –onto→ 𝐵 → 𝐹 : 𝐴 ⟶ 𝐵 ) |
21 |
|
fdm |
⊢ ( 𝐹 : 𝐴 ⟶ 𝐵 → dom 𝐹 = 𝐴 ) |
22 |
14 20 21
|
3syl |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → dom 𝐹 = 𝐴 ) |
23 |
19 22
|
sseqtrrd |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝑥 ⊆ dom 𝐹 ) |
24 |
|
fores |
⊢ ( ( Fun 𝐹 ∧ 𝑥 ⊆ dom 𝐹 ) → ( 𝐹 ↾ 𝑥 ) : 𝑥 –onto→ ( 𝐹 “ 𝑥 ) ) |
25 |
16 23 24
|
syl2anc |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → ( 𝐹 ↾ 𝑥 ) : 𝑥 –onto→ ( 𝐹 “ 𝑥 ) ) |
26 |
|
fodomnum |
⊢ ( 𝑥 ∈ dom card → ( ( 𝐹 ↾ 𝑥 ) : 𝑥 –onto→ ( 𝐹 “ 𝑥 ) → ( 𝐹 “ 𝑥 ) ≼ 𝑥 ) ) |
27 |
13 25 26
|
sylc |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → ( 𝐹 “ 𝑥 ) ≼ 𝑥 ) |
28 |
|
simpl1 |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝐴 ∈ 𝑉 ) |
29 |
|
ssdomg |
⊢ ( 𝐴 ∈ 𝑉 → ( 𝑥 ⊆ 𝐴 → 𝑥 ≼ 𝐴 ) ) |
30 |
28 19 29
|
sylc |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → 𝑥 ≼ 𝐴 ) |
31 |
|
domtr |
⊢ ( ( ( 𝐹 “ 𝑥 ) ≼ 𝑥 ∧ 𝑥 ≼ 𝐴 ) → ( 𝐹 “ 𝑥 ) ≼ 𝐴 ) |
32 |
27 30 31
|
syl2anc |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → ( 𝐹 “ 𝑥 ) ≼ 𝐴 ) |
33 |
|
breq1 |
⊢ ( ( 𝐹 “ 𝑥 ) = 𝐵 → ( ( 𝐹 “ 𝑥 ) ≼ 𝐴 ↔ 𝐵 ≼ 𝐴 ) ) |
34 |
32 33
|
syl5ibcom |
⊢ ( ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) ∧ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ) → ( ( 𝐹 “ 𝑥 ) = 𝐵 → 𝐵 ≼ 𝐴 ) ) |
35 |
34
|
rexlimdva |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → ( ∃ 𝑥 ∈ ( 𝒫 𝐴 ∩ Fin ) ( 𝐹 “ 𝑥 ) = 𝐵 → 𝐵 ≼ 𝐴 ) ) |
36 |
9 35
|
mpd |
⊢ ( ( 𝐴 ∈ 𝑉 ∧ 𝐵 ∈ Fin ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) → 𝐵 ≼ 𝐴 ) |