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;
then
(- 1) (#) g is_integrable_on P2M P
by MESFUNC6:102;
then
(- jj) (#) g is_integrable_on P
;
hence expect ((f - g),P) =
(expect (f,P)) + (expect (((- jj) (#) g),P))
by A1, Th26
.=
(expect (f,P)) + ((- 1) * (expect (g,P)))
by A2, Th27
.=
(expect (f,P)) - (expect (g,P))
;
verum