Metamath Proof Explorer


Theorem taylpval

Description: Value of the Taylor polynomial. (Contributed by Mario Carneiro, 31-Dec-2016)

Ref Expression
Hypotheses taylpfval.s φ S
taylpfval.f φ F : A
taylpfval.a φ A S
taylpfval.n φ N 0
taylpfval.b φ B dom S D n F N
taylpfval.t T = N S Tayl F B
taylpval.x φ X
Assertion taylpval φ T X = k = 0 N S D n F k B k ! X B k

Proof

Step Hyp Ref Expression
1 taylpfval.s φ S
2 taylpfval.f φ F : A
3 taylpfval.a φ A S
4 taylpfval.n φ N 0
5 taylpfval.b φ B dom S D n F N
6 taylpfval.t T = N S Tayl F B
7 taylpval.x φ X
8 1 2 3 4 5 6 taylpfval φ T = x k = 0 N S D n F k B k ! x B k
9 simplr φ x = X k 0 N x = X
10 9 oveq1d φ x = X k 0 N x B = X B
11 10 oveq1d φ x = X k 0 N x B k = X B k
12 11 oveq2d φ x = X k 0 N S D n F k B k ! x B k = S D n F k B k ! X B k
13 12 sumeq2dv φ x = X k = 0 N S D n F k B k ! x B k = k = 0 N S D n F k B k ! X B k
14 sumex k = 0 N S D n F k B k ! X B k V
15 14 a1i φ k = 0 N S D n F k B k ! X B k V
16 8 13 7 15 fvmptd φ T X = k = 0 N S D n F k B k ! X B k