let G be Graph; for pe being FinSequence of the carrier' of G
for W being Function st W is_weight_of G & len pe = 1 holds
cost pe,W = W . (pe . 1)
let pe be FinSequence of the carrier' of G; for W being Function st W is_weight_of G & len pe = 1 holds
cost pe,W = W . (pe . 1)
let W be Function; ( W is_weight_of G & len pe = 1 implies cost pe,W = W . (pe . 1) )
assume that
A1:
W is_weight_of G
and
A2:
len pe = 1
; cost pe,W = W . (pe . 1)
A3:
1 in dom pe
by A2, FINSEQ_3:27;
set f = RealSequence pe,W;
dom (RealSequence pe,W) = dom pe
by A1, GRAPH_5:def 15;
then
len (RealSequence pe,W) = 1
by A2, FINSEQ_3:31;
then A4:
RealSequence pe,W = <*((RealSequence pe,W) . 1)*>
by FINSEQ_1:57;
thus cost pe,W =
Sum (RealSequence pe,W)
by GRAPH_5:def 16
.=
(RealSequence pe,W) . 1
by A4, FINSOP_1:12
.=
W . (pe . 1)
by A1, A3, GRAPH_5:def 15
; verum