Metamath Proof Explorer


Theorem iunrnmptss

Description: A subset relation for an indexed union over the range of function expressed as a mapping. (Contributed by Thierry Arnoux, 27-Mar-2018)

Ref Expression
Hypotheses iunrnmptss.1 y = B C = D
iunrnmptss.2 φ x A B V
Assertion iunrnmptss φ y ran x A B C x A D

Proof

Step Hyp Ref Expression
1 iunrnmptss.1 y = B C = D
2 iunrnmptss.2 φ x A B V
3 df-rex y ran x A B z C y y ran x A B z C
4 2 ralrimiva φ x A B V
5 eqid x A B = x A B
6 5 elrnmptg x A B V y ran x A B x A y = B
7 4 6 syl φ y ran x A B x A y = B
8 7 anbi1d φ y ran x A B z C x A y = B z C
9 8 exbidv φ y y ran x A B z C y x A y = B z C
10 r19.41v x A y = B z C x A y = B z C
11 1 eleq2d y = B z C z D
12 11 biimpa y = B z C z D
13 12 reximi x A y = B z C x A z D
14 10 13 sylbir x A y = B z C x A z D
15 14 exlimiv y x A y = B z C x A z D
16 9 15 syl6bi φ y y ran x A B z C x A z D
17 3 16 syl5bi φ y ran x A B z C x A z D
18 17 ss2abdv φ z | y ran x A B z C z | x A z D
19 df-iun y ran x A B C = z | y ran x A B z C
20 df-iun x A D = z | x A z D
21 18 19 20 3sstr4g φ y ran x A B C x A D