let m, n be non empty Element of NAT ; for f being PartFunc of (REAL m),(REAL n)
for x being Element of REAL m st f is_differentiable_in x holds
diff f,x is LinearOperator of (REAL-NS m),(REAL-NS n)
let f be PartFunc of (REAL m),(REAL n); for x being Element of REAL m st f is_differentiable_in x holds
diff f,x is LinearOperator of (REAL-NS m),(REAL-NS n)
let x be Element of REAL m; ( f is_differentiable_in x implies diff f,x is LinearOperator of (REAL-NS m),(REAL-NS n) )
assume
f is_differentiable_in x
; diff f,x is LinearOperator of (REAL-NS m),(REAL-NS n)
then
diff f,x is Point of (R_NormSpace_of_BoundedLinearOperators (REAL-NS m),(REAL-NS n))
by LMBOP1;
hence
diff f,x is LinearOperator of (REAL-NS m),(REAL-NS n)
by LOPBAN_1:def 10; verum