Metamath Proof Explorer


Theorem fin

Description: Mapping into an intersection. (Contributed by NM, 14-Sep-1999) (Proof shortened by Andrew Salmon, 17-Sep-2011)

Ref Expression
Assertion fin F : A B C F : A B F : A C

Proof

Step Hyp Ref Expression
1 ssin ran F B ran F C ran F B C
2 1 anbi2i F Fn A ran F B ran F C F Fn A ran F B C
3 anandi F Fn A ran F B ran F C F Fn A ran F B F Fn A ran F C
4 2 3 bitr3i F Fn A ran F B C F Fn A ran F B F Fn A ran F C
5 df-f F : A B C F Fn A ran F B C
6 df-f F : A B F Fn A ran F B
7 df-f F : A C F Fn A ran F C
8 6 7 anbi12i F : A B F : A C F Fn A ran F B F Fn A ran F C
9 4 5 8 3bitr4i F : A B C F : A B F : A C