Metamath Proof Explorer


Theorem djurf1o

Description: The right injection function on all sets is one to one and onto. (Contributed by Jim Kingdon, 22-Jun-2022)

Ref Expression
Assertion djurf1o inr:V1-1 onto1𝑜×V

Proof

Step Hyp Ref Expression
1 df-inr inr=xV1𝑜x
2 1onn 1𝑜ω
3 snidg 1𝑜ω1𝑜1𝑜
4 2 3 ax-mp 1𝑜1𝑜
5 opelxpi 1𝑜1𝑜xV1𝑜x1𝑜×V
6 4 5 mpan xV1𝑜x1𝑜×V
7 6 adantl xV1𝑜x1𝑜×V
8 fvexd y1𝑜×V2ndyV
9 1st2nd2 y1𝑜×Vy=1sty2ndy
10 xp1st y1𝑜×V1sty1𝑜
11 elsni 1sty1𝑜1sty=1𝑜
12 10 11 syl y1𝑜×V1sty=1𝑜
13 12 opeq1d y1𝑜×V1sty2ndy=1𝑜2ndy
14 9 13 eqtrd y1𝑜×Vy=1𝑜2ndy
15 14 eqeq2d y1𝑜×V1𝑜x=y1𝑜x=1𝑜2ndy
16 eqcom 1𝑜x=yy=1𝑜x
17 eqid 1𝑜=1𝑜
18 1oex 1𝑜V
19 vex xV
20 18 19 opth 1𝑜x=1𝑜2ndy1𝑜=1𝑜x=2ndy
21 17 20 mpbiran 1𝑜x=1𝑜2ndyx=2ndy
22 15 16 21 3bitr3g y1𝑜×Vy=1𝑜xx=2ndy
23 22 bicomd y1𝑜×Vx=2ndyy=1𝑜x
24 23 ad2antll xVy1𝑜×Vx=2ndyy=1𝑜x
25 1 7 8 24 f1o2d inr:V1-1 onto1𝑜×V
26 25 mptru inr:V1-1 onto1𝑜×V