Metamath Proof Explorer


Theorem relssdmrnOLD

Description: Obsolete version of relssdmrn as of 23-Dec-2024. (Contributed by NM, 3-Aug-1994) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion relssdmrnOLD RelAAdomA×ranA

Proof

Step Hyp Ref Expression
1 id RelARelA
2 19.8a xyAyxyA
3 19.8a xyAxxyA
4 opelxp xydomA×ranAxdomAyranA
5 vex xV
6 5 eldm2 xdomAyxyA
7 vex yV
8 7 elrn2 yranAxxyA
9 6 8 anbi12i xdomAyranAyxyAxxyA
10 4 9 bitri xydomA×ranAyxyAxxyA
11 2 3 10 sylanbrc xyAxydomA×ranA
12 11 a1i RelAxyAxydomA×ranA
13 1 12 relssdv RelAAdomA×ranA