let D be non empty set ; for F being PartFunc of D,REAL
for X being set
for r being Real
for Y being finite set st Y = dom (F | X) holds
Sum (F - r),X = (Sum F,X) - (r * (card Y))
let F be PartFunc of D,REAL ; for X being set
for r being Real
for Y being finite set st Y = dom (F | X) holds
Sum (F - r),X = (Sum F,X) - (r * (card Y))
let X be set ; for r being Real
for Y being finite set st Y = dom (F | X) holds
Sum (F - r),X = (Sum F,X) - (r * (card Y))
let r be Real; for Y being finite set st Y = dom (F | X) holds
Sum (F - r),X = (Sum F,X) - (r * (card Y))
set fx = FinS F,X;
let Y be finite set ; ( Y = dom (F | X) implies Sum (F - r),X = (Sum F,X) - (r * (card Y)) )
set dr = (card Y) |-> r;
assume A1:
Y = dom (F | X)
; Sum (F - r),X = (Sum F,X) - (r * (card Y))
then
len (FinS F,X) = card Y
by Th70;
then reconsider xf = FinS F,X, rd = (card Y) |-> r as Element of (card Y) -tuples_on REAL by FINSEQ_2:110;
FinS (F - r),X = (FinS F,X) - ((card Y) |-> r)
by A1, Th76;
hence Sum (F - r),X =
(Sum xf) - (Sum rd)
by RVSUM_1:120
.=
(Sum F,X) - (r * (card Y))
by RVSUM_1:110
;
verum