theorem :: VFUNCT_2:28

for M being non empty set
for V being ComplexNormSpace
for f2 being PartFunc of M,V
for X being set
for f1 being PartFunc of M,COMPLEX holds
( (f1 (#) f2) | X = (f1 | X) (#) (f2 | X) & (f1 (#) f2) | X = (f1 | X) (#) f2 & (f1 (#) f2) | X = f1 (#) (f2 | X) )