let Omega be non empty set ; for Sigma being SigmaField of Omega
for P being Probability of Sigma
for f, g being Real-Valued-Random-Variable of Sigma st f is_integrable_on P & g is_integrable_on P holds
expect (f - g),P = (expect f,P) - (expect g,P)
let Sigma be SigmaField of Omega; for P being Probability of Sigma
for f, g being Real-Valued-Random-Variable of Sigma st f is_integrable_on P & g is_integrable_on P holds
expect (f - g),P = (expect f,P) - (expect g,P)
let P be Probability of Sigma; for f, g being Real-Valued-Random-Variable of Sigma st f is_integrable_on P & g is_integrable_on P holds
expect (f - g),P = (expect f,P) - (expect g,P)
let f, g be Real-Valued-Random-Variable of Sigma; ( f is_integrable_on P & g is_integrable_on P implies expect (f - g),P = (expect f,P) - (expect g,P) )
assume that
A1:
f is_integrable_on P
and
A2:
g is_integrable_on P
; expect (f - g),P = (expect f,P) - (expect g,P)
g is_integrable_on P2M P
by A2, Def3;
then
(- 1) (#) g is_integrable_on P2M P
by MESFUNC6:102;
then
(- 1) (#) g is_integrable_on P
by Def3;
hence expect (f - g),P =
(expect f,P) + (expect ((- 1) (#) g),P)
by A1, Th26
.=
(expect f,P) + ((- 1) * (expect g,P))
by A2, Th27
.=
(expect f,P) - (expect g,P)
;
verum