Metamath Proof Explorer


Theorem xrhval

Description: The value of the embedding from the extended real numbers into a complete lattice. (Contributed by Thierry Arnoux, 19-Feb-2018)

Ref Expression
Hypotheses xrhval.b B=ℝHomR
xrhval.l L=glbR
xrhval.u U=lubR
Assertion xrhval RV *HomR=x*ifxℝHomRxifx=+∞UBLB

Proof

Step Hyp Ref Expression
1 xrhval.b B=ℝHomR
2 xrhval.l L=glbR
3 xrhval.u U=lubR
4 elex RVRV
5 fveq2 r=RℝHomr=ℝHomR
6 5 fveq1d r=RℝHomrx=ℝHomRx
7 fveq2 r=Rlubr=lubR
8 7 3 eqtr4di r=Rlubr=U
9 5 imaeq1d r=RℝHomr=ℝHomR
10 9 1 eqtr4di r=RℝHomr=B
11 8 10 fveq12d r=RlubrℝHomr=UB
12 fveq2 r=Rglbr=glbR
13 12 2 eqtr4di r=Rglbr=L
14 13 10 fveq12d r=RglbrℝHomr=LB
15 11 14 ifeq12d r=Rifx=+∞lubrℝHomrglbrℝHomr=ifx=+∞UBLB
16 6 15 ifeq12d r=RifxℝHomrxifx=+∞lubrℝHomrglbrℝHomr=ifxℝHomRxifx=+∞UBLB
17 16 mpteq2dv r=Rx*ifxℝHomrxifx=+∞lubrℝHomrglbrℝHomr=x*ifxℝHomRxifx=+∞UBLB
18 df-xrh *Hom=rVx*ifxℝHomrxifx=+∞lubrℝHomrglbrℝHomr
19 xrex *V
20 19 mptex x*ifxℝHomRxifx=+∞UBLBV
21 17 18 20 fvmpt RV *HomR=x*ifxℝHomRxifx=+∞UBLB
22 4 21 syl RV *HomR=x*ifxℝHomRxifx=+∞UBLB