theorem Th62: :: INTEGR24:62

for f being PartFunc of REAL,REAL
for a, b, r being Real st ].a,b.[ c= dom f & f is_improper_integrable_on a,b holds
( - f is_improper_integrable_on a,b & improper_integral ((- f),a,b) = - (improper_integral (f,a,b)) )