Metamath Proof Explorer


Definition df-tayl

Description: Define the Taylor polynomial or Taylor series of a function. TODO-AV: n e. ( NN0 u. { +oo } ) should be replaced by n e. NN0* . (Contributed by Mario Carneiro, 30-Dec-2016)

Ref Expression
Assertion df-tayl Tayl = ( 𝑠 ∈ { ℝ , ℂ } , 𝑓 ∈ ( ℂ ↑pm 𝑠 ) ↦ ( 𝑛 ∈ ( ℕ0 ∪ { +∞ } ) , 𝑎 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ↦ 𝑥 ∈ ℂ ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 ctayl Tayl
1 vs 𝑠
2 cr
3 cc
4 2 3 cpr { ℝ , ℂ }
5 vf 𝑓
6 cpm pm
7 1 cv 𝑠
8 3 7 6 co ( ℂ ↑pm 𝑠 )
9 vn 𝑛
10 cn0 0
11 cpnf +∞
12 11 csn { +∞ }
13 10 12 cun ( ℕ0 ∪ { +∞ } )
14 va 𝑎
15 vk 𝑘
16 cc0 0
17 cicc [,]
18 9 cv 𝑛
19 16 18 17 co ( 0 [,] 𝑛 )
20 cz
21 19 20 cin ( ( 0 [,] 𝑛 ) ∩ ℤ )
22 cdvn D𝑛
23 5 cv 𝑓
24 7 23 22 co ( 𝑠 D𝑛 𝑓 )
25 15 cv 𝑘
26 25 24 cfv ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 )
27 26 cdm dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 )
28 15 21 27 ciin 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 )
29 vx 𝑥
30 29 cv 𝑥
31 30 csn { 𝑥 }
32 ccnfld fld
33 ctsu tsums
34 14 cv 𝑎
35 34 26 cfv ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 )
36 cdiv /
37 cfa !
38 25 37 cfv ( ! ‘ 𝑘 )
39 35 38 36 co ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) )
40 cmul ·
41 cmin
42 30 34 41 co ( 𝑥𝑎 )
43 cexp
44 42 25 43 co ( ( 𝑥𝑎 ) ↑ 𝑘 )
45 39 44 40 co ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) )
46 15 21 45 cmpt ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) )
47 32 46 33 co ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) )
48 31 47 cxp ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) )
49 29 3 48 ciun 𝑥 ∈ ℂ ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) )
50 9 14 13 28 49 cmpo ( 𝑛 ∈ ( ℕ0 ∪ { +∞ } ) , 𝑎 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ↦ 𝑥 ∈ ℂ ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) ) )
51 1 5 4 8 50 cmpo ( 𝑠 ∈ { ℝ , ℂ } , 𝑓 ∈ ( ℂ ↑pm 𝑠 ) ↦ ( 𝑛 ∈ ( ℕ0 ∪ { +∞ } ) , 𝑎 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ↦ 𝑥 ∈ ℂ ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) ) ) )
52 0 51 wceq Tayl = ( 𝑠 ∈ { ℝ , ℂ } , 𝑓 ∈ ( ℂ ↑pm 𝑠 ) ↦ ( 𝑛 ∈ ( ℕ0 ∪ { +∞ } ) , 𝑎 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) dom ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ↦ 𝑥 ∈ ℂ ( { 𝑥 } × ( ℂfld tsums ( 𝑘 ∈ ( ( 0 [,] 𝑛 ) ∩ ℤ ) ↦ ( ( ( ( ( 𝑠 D𝑛 𝑓 ) ‘ 𝑘 ) ‘ 𝑎 ) / ( ! ‘ 𝑘 ) ) · ( ( 𝑥𝑎 ) ↑ 𝑘 ) ) ) ) ) ) )