Metamath Proof Explorer


Theorem oppglemOLD

Description: Obsolete version of setsplusg as of 18-Oct-2024. Lemma for oppgbas . (Contributed by Stefan O'Rear, 26-Aug-2015) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses oppgbas.1 O=opp𝑔R
oppglemOLD.2 E=SlotN
oppglemOLD.3 N
oppglemOLD.4 N2
Assertion oppglemOLD ER=EO

Proof

Step Hyp Ref Expression
1 oppgbas.1 O=opp𝑔R
2 oppglemOLD.2 E=SlotN
3 oppglemOLD.3 N
4 oppglemOLD.4 N2
5 2 3 ndxid E=SlotEndx
6 2 3 ndxarg Endx=N
7 plusgndx +ndx=2
8 6 7 neeq12i Endx+ndxN2
9 4 8 mpbir Endx+ndx
10 5 9 setsnid ER=ERsSet+ndxtpos+R
11 eqid +R=+R
12 11 1 oppgval O=RsSet+ndxtpos+R
13 12 fveq2i EO=ERsSet+ndxtpos+R
14 10 13 eqtr4i ER=EO