theorem :: INTEGRA7:15

for X being set
for f, g, F, G being PartFunc of REAL,REAL st ( for x being set st x in X holds
G . x <> 0 ) & F is_integral_of f,X & G is_integral_of g,X holds
F / G is_integral_of ((f (#) G) - (F (#) g)) / (G (#) G),X