let X1, X2 be non empty set ; for S1 being SigmaField of X1
for S2 being SigmaField of X2
for M1 being sigma_Measure of S1
for M2 being sigma_Measure of S2
for V being Element of sigma (measurable_rectangles (S1,S2))
for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let S1 be SigmaField of X1; for S2 being SigmaField of X2
for M1 being sigma_Measure of S1
for M2 being sigma_Measure of S2
for V being Element of sigma (measurable_rectangles (S1,S2))
for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let S2 be SigmaField of X2; for M1 being sigma_Measure of S1
for M2 being sigma_Measure of S2
for V being Element of sigma (measurable_rectangles (S1,S2))
for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let M1 be sigma_Measure of S1; for M2 being sigma_Measure of S2
for V being Element of sigma (measurable_rectangles (S1,S2))
for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let M2 be sigma_Measure of S2; for V being Element of sigma (measurable_rectangles (S1,S2))
for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let V be Element of sigma (measurable_rectangles (S1,S2)); for A being Element of S1
for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let A be Element of S1; for B being Element of S2 st M1 is sigma_finite & V = [:A,B:] holds
Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let B be Element of S2; ( M1 is sigma_finite & V = [:A,B:] implies Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) } )
assume A1:
( M1 is sigma_finite & V = [:A,B:] )
; Field_generated_by (measurable_rectangles (S1,S2)) c= { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
let E be object ; TARSKI:def 3 ( not E in Field_generated_by (measurable_rectangles (S1,S2)) or E in { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) } )
assume A2:
E in Field_generated_by (measurable_rectangles (S1,S2))
; E in { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
sigma (measurable_rectangles (S1,S2)) =
sigma (DisUnion (measurable_rectangles (S1,S2)))
by Th1
.=
sigma (Field_generated_by (measurable_rectangles (S1,S2)))
by SRINGS_3:22
;
then
Field_generated_by (measurable_rectangles (S1,S2)) c= sigma (measurable_rectangles (S1,S2))
by PROB_1:def 9;
then reconsider E1 = E as Element of sigma (measurable_rectangles (S1,S2)) by A2;
E1 in Field_generated_by (measurable_rectangles (S1,S2))
by A2;
hence
E in { E where E is Element of sigma (measurable_rectangles (S1,S2)) : Integral (M2,(X-vol ((E /\ V),M1))) = (product_sigma_Measure (M1,M2)) . (E /\ V) }
by A1, Th105; verum