theorem Th26: :: INTEGR19:26

for n being Element of NAT
for a, b, c, d being Real
for f being PartFunc of REAL,(REAL n) st a <= b & f is_integrable_on ['a,b'] & f | ['a,b'] is bounded & ['a,b'] c= dom f & c in ['a,b'] & d in ['a,b'] holds
integral ((- f),c,d) = - (integral (f,c,d))