Metamath Proof Explorer


Theorem maprnin

Description: Restricting the range of the mapping operator. (Contributed by Thierry Arnoux, 30-Aug-2017)

Ref Expression
Hypotheses maprnin.1 A V
maprnin.2 B V
Assertion maprnin B C A = f B A | ran f C

Proof

Step Hyp Ref Expression
1 maprnin.1 A V
2 maprnin.2 B V
3 ffn f : A B f Fn A
4 df-f f : A C f Fn A ran f C
5 4 baibr f Fn A ran f C f : A C
6 3 5 syl f : A B ran f C f : A C
7 6 pm5.32i f : A B ran f C f : A B f : A C
8 2 1 elmap f B A f : A B
9 8 anbi1i f B A ran f C f : A B ran f C
10 fin f : A B C f : A B f : A C
11 7 9 10 3bitr4ri f : A B C f B A ran f C
12 11 abbii f | f : A B C = f | f B A ran f C
13 2 inex1 B C V
14 13 1 mapval B C A = f | f : A B C
15 df-rab f B A | ran f C = f | f B A ran f C
16 12 14 15 3eqtr4i B C A = f B A | ran f C