theorem Th24: :: NDIFF_4:24

for i being Element of NAT
for n being non zero Element of NAT
for g being PartFunc of REAL,(REAL-NS n)
for x0 being Real st 1 <= i & i <= n & g is_differentiable_in x0 holds
( (Proj (i,n)) * g is_differentiable_in x0 & (Proj (i,n)) . (diff (g,x0)) = diff (((Proj (i,n)) * g),x0) )