let f be PartFunc of REAL,REAL; for a, b being Real
for A being non empty Subset of REAL st [.a,b.[ c= dom f & A = [.a,b.[ & f is_right_improper_integrable_on a,b & abs f is_right_ext_Riemann_integrable_on a,b & f | A is nonnegative holds
( f | A is_integrable_on L-Meas & right_improper_integral (f,a,b) = Integral (L-Meas,(f | A)) )
let a, b be Real; for A being non empty Subset of REAL st [.a,b.[ c= dom f & A = [.a,b.[ & f is_right_improper_integrable_on a,b & abs f is_right_ext_Riemann_integrable_on a,b & f | A is nonnegative holds
( f | A is_integrable_on L-Meas & right_improper_integral (f,a,b) = Integral (L-Meas,(f | A)) )
let A be non empty Subset of REAL; ( [.a,b.[ c= dom f & A = [.a,b.[ & f is_right_improper_integrable_on a,b & abs f is_right_ext_Riemann_integrable_on a,b & f | A is nonnegative implies ( f | A is_integrable_on L-Meas & right_improper_integral (f,a,b) = Integral (L-Meas,(f | A)) ) )
assume that
A1:
[.a,b.[ c= dom f
and
A2:
A = [.a,b.[
and
A3:
f is_right_improper_integrable_on a,b
and
A4:
abs f is_right_ext_Riemann_integrable_on a,b
and
A5:
f | A is nonnegative
; ( f | A is_integrable_on L-Meas & right_improper_integral (f,a,b) = Integral (L-Meas,(f | A)) )
a < b
by A2, XXREAL_1:27;
then
f is_right_ext_Riemann_integrable_on a,b
by A1, A3, A4, Th57;
hence
( f | A is_integrable_on L-Meas & right_improper_integral (f,a,b) = Integral (L-Meas,(f | A)) )
by A1, A2, A3, A5, Th41; verum