let X be non empty set ; for S being SigmaField of X
for M being sigma_Measure of S
for f, g being PartFunc of X,REAL st f is_integrable_on M & g is_integrable_on M holds
f - g is_integrable_on M
let S be SigmaField of X; for M being sigma_Measure of S
for f, g being PartFunc of X,REAL st f is_integrable_on M & g is_integrable_on M holds
f - g is_integrable_on M
let M be sigma_Measure of S; for f, g being PartFunc of X,REAL st f is_integrable_on M & g is_integrable_on M holds
f - g is_integrable_on M
let f, g be PartFunc of X,REAL; ( f is_integrable_on M & g is_integrable_on M implies f - g is_integrable_on M )
assume that
A1:
f is_integrable_on M
and
A2:
g is_integrable_on M
; f - g is_integrable_on M
R_EAL g is_integrable_on M
by A2, MESFUNC6:def 4;
then
(- 1) (#) (R_EAL g) is_integrable_on M
by MESFUNC5:110;
then
- (R_EAL g) is_integrable_on M
by MESFUNC2:9;
then A3:
R_EAL (- g) is_integrable_on M
by MESFUNC6:28;
R_EAL f is_integrable_on M
by A1, MESFUNC6:def 4;
then
(R_EAL f) + (R_EAL (- g)) is_integrable_on M
by A3, MESFUNC5:108;
then
R_EAL (f - g) is_integrable_on M
by MESFUNC6:23;
hence
f - g is_integrable_on M
by MESFUNC6:def 4; verum