theorem
for
a,
b,
c being
Real for
f being
Function of
REAL,
REAL st
a < b &
b <= c &
f is_integrable_on ['a,c'] &
f | ['a,c'] is
bounded & ( for
x being
Real st
x in ['b,c'] holds
f . x = 0 ) holds
centroid (
f,
['a,c'])
= centroid (
f,
['a,b'])