theorem Th71: :: PDIFF_9:71

for m being non zero Element of NAT
for Z being Subset of (REAL m)
for i being Nat
for f being PartFunc of (REAL m),REAL st Z is open & 1 <= i & i <= m & f is_partial_differentiable_on Z,i holds
f `partial| (Z,i) = (f | Z) `partial| (Z,i)