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=xA,yBC
Assertion rnmposs xAyBCDranFD

Proof

Step Hyp Ref Expression
1 rnmposs.1 F=xA,yBC
2 1 rnmpo ranF=z|xAyBz=C
3 2 eqabri zranFxAyBz=C
4 2r19.29 xAyBCDxAyBz=CxAyBCDz=C
5 eleq1 z=CzDCD
6 5 biimparc CDz=CzD
7 6 a1i xAyBCDz=CzD
8 7 rexlimivv xAyBCDz=CzD
9 4 8 syl xAyBCDxAyBz=CzD
10 9 ex xAyBCDxAyBz=CzD
11 3 10 biimtrid xAyBCDzranFzD
12 11 ssrdv xAyBCDranFD