Metamath Proof Explorer


Theorem ringsubdir

Description: Ring multiplication distributes over subtraction. ( subdir analog.) (Contributed by Jeff Madsen, 19-Jun-2010) (Revised by Mario Carneiro, 2-Jul-2014)

Ref Expression
Hypotheses ringsubdi.b B=BaseR
ringsubdi.t ·˙=R
ringsubdi.m -˙=-R
ringsubdi.r φRRing
ringsubdi.x φXB
ringsubdi.y φYB
ringsubdi.z φZB
Assertion ringsubdir φX-˙Y·˙Z=X·˙Z-˙Y·˙Z

Proof

Step Hyp Ref Expression
1 ringsubdi.b B=BaseR
2 ringsubdi.t ·˙=R
3 ringsubdi.m -˙=-R
4 ringsubdi.r φRRing
5 ringsubdi.x φXB
6 ringsubdi.y φYB
7 ringsubdi.z φZB
8 ringgrp RRingRGrp
9 4 8 syl φRGrp
10 eqid invgR=invgR
11 1 10 grpinvcl RGrpYBinvgRYB
12 9 6 11 syl2anc φinvgRYB
13 eqid +R=+R
14 1 13 2 ringdir RRingXBinvgRYBZBX+RinvgRY·˙Z=X·˙Z+RinvgRY·˙Z
15 4 5 12 7 14 syl13anc φX+RinvgRY·˙Z=X·˙Z+RinvgRY·˙Z
16 1 2 10 4 6 7 ringmneg1 φinvgRY·˙Z=invgRY·˙Z
17 16 oveq2d φX·˙Z+RinvgRY·˙Z=X·˙Z+RinvgRY·˙Z
18 15 17 eqtrd φX+RinvgRY·˙Z=X·˙Z+RinvgRY·˙Z
19 1 13 10 3 grpsubval XBYBX-˙Y=X+RinvgRY
20 5 6 19 syl2anc φX-˙Y=X+RinvgRY
21 20 oveq1d φX-˙Y·˙Z=X+RinvgRY·˙Z
22 1 2 ringcl RRingXBZBX·˙ZB
23 4 5 7 22 syl3anc φX·˙ZB
24 1 2 ringcl RRingYBZBY·˙ZB
25 4 6 7 24 syl3anc φY·˙ZB
26 1 13 10 3 grpsubval X·˙ZBY·˙ZBX·˙Z-˙Y·˙Z=X·˙Z+RinvgRY·˙Z
27 23 25 26 syl2anc φX·˙Z-˙Y·˙Z=X·˙Z+RinvgRY·˙Z
28 18 21 27 3eqtr4d φX-˙Y·˙Z=X·˙Z-˙Y·˙Z