theorem :: FUZZY_7:34

for A being non empty closed_interval Subset of REAL
for a, b, c being Real
for f being Function of REAL,REAL st b > 0 & c > 0 & ['(a - c),(a + c)'] c= A & ( for x being Real holds f . x = max (0,(b - |.((b * (x - a)) / c).|)) ) holds
centroid (f,A) = a