Metamath Proof Explorer


Theorem mapdhval2

Description: Lemmma for ~? mapdh . (Contributed by NM, 3-Apr-2015)

Ref Expression
Hypotheses mapdh.q Q=0C
mapdh.i I=xVif2ndx=0˙QιhD|MN2ndx=JhMN1st1stx-˙2ndx=J2nd1stxRh
mapdh2.x φXA
mapdh2.f φFB
mapdh2.y φYV0˙
Assertion mapdhval2 φIXFY=ιhD|MNY=JhMNX-˙Y=JFRh

Proof

Step Hyp Ref Expression
1 mapdh.q Q=0C
2 mapdh.i I=xVif2ndx=0˙QιhD|MN2ndx=JhMN1st1stx-˙2ndx=J2nd1stxRh
3 mapdh2.x φXA
4 mapdh2.f φFB
5 mapdh2.y φYV0˙
6 1 2 3 4 5 mapdhval φIXFY=ifY=0˙QιhD|MNY=JhMNX-˙Y=JFRh
7 eldifsni YV0˙Y0˙
8 7 neneqd YV0˙¬Y=0˙
9 iffalse ¬Y=0˙ifY=0˙QιhD|MNY=JhMNX-˙Y=JFRh=ιhD|MNY=JhMNX-˙Y=JFRh
10 5 8 9 3syl φifY=0˙QιhD|MNY=JhMNX-˙Y=JFRh=ιhD|MNY=JhMNX-˙Y=JFRh
11 6 10 eqtrd φIXFY=ιhD|MNY=JhMNX-˙Y=JFRh