Metamath Proof Explorer


Theorem rnmposs

Description: The range of an operation given by the maps-to notation as a subset. (Contributed by Thierry Arnoux, 23-May-2017)

Ref Expression
Hypothesis rnmposs.1 F = x A , y B C
Assertion rnmposs x A y B C D ran F D

Proof

Step Hyp Ref Expression
1 rnmposs.1 F = x A , y B C
2 1 rnmpo ran F = z | x A y B z = C
3 2 abeq2i z ran F x A y B z = C
4 2r19.29 x A y B C D x A y B z = C x A y B C D z = C
5 eleq1 z = C z D C D
6 5 biimparc C D z = C z D
7 6 a1i x A y B C D z = C z D
8 7 rexlimivv x A y B C D z = C z D
9 4 8 syl x A y B C D x A y B z = C z D
10 9 ex x A y B C D x A y B z = C z D
11 3 10 syl5bi x A y B C D z ran F z D
12 11 ssrdv x A y B C D ran F D