Proof of Theorem fin
| Step | Hyp | Ref
| Expression |
| 1 | | anidm 331 |
. . . 4
⊢ ((F Fn
A ∧ F Fn A) ↔
F Fn A) |
| 2 | | ssin 1659 |
. . . 4
⊢ ((ran F ⊆ B
∧ ran F ⊆ C) ↔ ran F
⊆ (B ∩ C)) |
| 3 | 1, 2 | anbi12i 369 |
. . 3
⊢ (((F
Fn A ∧ F Fn A) ∧
(ran F ⊆ B ∧ ran F
⊆ C)) ↔ (F Fn A ∧ ran
F ⊆ (B ∩ C))) |
| 4 | | an4 388 |
. . 3
⊢ (((F
Fn A ∧ F Fn A) ∧
(ran F ⊆ B ∧ ran F
⊆ C)) ↔ ((F Fn A ∧ ran
F ⊆ B) ∧ (F Fn
A ∧ ran F ⊆ C))) |
| 5 | 3, 4 | bitr3 153 |
. 2
⊢ ((F Fn
A ∧ ran F ⊆ (B
∩ C)) ↔ ((F Fn A ∧ ran
F ⊆ B) ∧ (F Fn
A ∧ ran F ⊆ C))) |
| 6 | | df-f 2434 |
. 2
⊢ (F:A–→(B
∩ C) ↔ (F Fn A ∧ ran
F ⊆ (B ∩ C))) |
| 7 | | df-f 2434 |
. . 3
⊢ (F:A–→B
↔ (F Fn A ∧ ran F
⊆ B)) |
| 8 | | df-f 2434 |
. . 3
⊢ (F:A–→C
↔ (F Fn A ∧ ran F
⊆ C)) |
| 9 | 7, 8 | anbi12i 369 |
. 2
⊢ ((F:A–→B
∧ F:A–→C)
↔ ((F Fn A ∧ ran F
⊆ B) ∧ (F Fn A ∧ ran
F ⊆ C))) |
| 10 | 5, 6, 9 | 3bitr4 158 |
1
⊢ (F:A–→(B
∩ C) ↔ (F:A–→B
∧ F:A–→C)) |