Metamath Proof Explorer


Theorem dvnff

Description: The iterated derivative is a function. (Contributed by Mario Carneiro, 11-Feb-2015)

Ref Expression
Assertion dvnff ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( 𝑆 D𝑛 𝐹 ) : ℕ0 ⟶ ( ℂ ↑pm dom 𝐹 ) )

Proof

Step Hyp Ref Expression
1 nn0uz 0 = ( ℤ ‘ 0 )
2 0zd ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → 0 ∈ ℤ )
3 fvconst2g ( ( 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ∧ 𝑘 ∈ ℕ0 ) → ( ( ℕ0 × { 𝐹 } ) ‘ 𝑘 ) = 𝐹 )
4 3 adantll ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → ( ( ℕ0 × { 𝐹 } ) ‘ 𝑘 ) = 𝐹 )
5 dmexg ( 𝐹 ∈ ( ℂ ↑pm 𝑆 ) → dom 𝐹 ∈ V )
6 5 ad2antlr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → dom 𝐹 ∈ V )
7 cnex ℂ ∈ V
8 7 a1i ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → ℂ ∈ V )
9 elpm2g ( ( ℂ ∈ V ∧ 𝑆 ∈ { ℝ , ℂ } ) → ( 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ↔ ( 𝐹 : dom 𝐹 ⟶ ℂ ∧ dom 𝐹𝑆 ) ) )
10 7 9 mpan ( 𝑆 ∈ { ℝ , ℂ } → ( 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ↔ ( 𝐹 : dom 𝐹 ⟶ ℂ ∧ dom 𝐹𝑆 ) ) )
11 10 biimpa ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( 𝐹 : dom 𝐹 ⟶ ℂ ∧ dom 𝐹𝑆 ) )
12 11 simpld ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → 𝐹 : dom 𝐹 ⟶ ℂ )
13 12 adantr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → 𝐹 : dom 𝐹 ⟶ ℂ )
14 fpmg ( ( dom 𝐹 ∈ V ∧ ℂ ∈ V ∧ 𝐹 : dom 𝐹 ⟶ ℂ ) → 𝐹 ∈ ( ℂ ↑pm dom 𝐹 ) )
15 6 8 13 14 syl3anc ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → 𝐹 ∈ ( ℂ ↑pm dom 𝐹 ) )
16 4 15 eqeltrd ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ 𝑘 ∈ ℕ0 ) → ( ( ℕ0 × { 𝐹 } ) ‘ 𝑘 ) ∈ ( ℂ ↑pm dom 𝐹 ) )
17 vex 𝑘 ∈ V
18 vex 𝑛 ∈ V
19 17 18 algrflem ( 𝑘 ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) 𝑛 ) = ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ‘ 𝑘 )
20 oveq2 ( 𝑥 = 𝑘 → ( 𝑆 D 𝑥 ) = ( 𝑆 D 𝑘 ) )
21 eqid ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) = ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) )
22 ovex ( 𝑆 D 𝑘 ) ∈ V
23 20 21 22 fvmpt ( 𝑘 ∈ V → ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ‘ 𝑘 ) = ( 𝑆 D 𝑘 ) )
24 23 elv ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ‘ 𝑘 ) = ( 𝑆 D 𝑘 )
25 19 24 eqtri ( 𝑘 ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) 𝑛 ) = ( 𝑆 D 𝑘 )
26 7 a1i ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ℂ ∈ V )
27 5 ad2antlr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom 𝐹 ∈ V )
28 dvfg ( 𝑆 ∈ { ℝ , ℂ } → ( 𝑆 D 𝑘 ) : dom ( 𝑆 D 𝑘 ) ⟶ ℂ )
29 28 ad2antrr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ( 𝑆 D 𝑘 ) : dom ( 𝑆 D 𝑘 ) ⟶ ℂ )
30 recnprss ( 𝑆 ∈ { ℝ , ℂ } → 𝑆 ⊆ ℂ )
31 30 ad2antrr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → 𝑆 ⊆ ℂ )
32 simprl ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) )
33 elpm2g ( ( ℂ ∈ V ∧ dom 𝐹 ∈ V ) → ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ↔ ( 𝑘 : dom 𝑘 ⟶ ℂ ∧ dom 𝑘 ⊆ dom 𝐹 ) ) )
34 7 27 33 sylancr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ↔ ( 𝑘 : dom 𝑘 ⟶ ℂ ∧ dom 𝑘 ⊆ dom 𝐹 ) ) )
35 32 34 mpbid ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ( 𝑘 : dom 𝑘 ⟶ ℂ ∧ dom 𝑘 ⊆ dom 𝐹 ) )
36 35 simpld ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → 𝑘 : dom 𝑘 ⟶ ℂ )
37 35 simprd ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom 𝑘 ⊆ dom 𝐹 )
38 11 simprd ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → dom 𝐹𝑆 )
39 38 adantr ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom 𝐹𝑆 )
40 37 39 sstrd ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom 𝑘𝑆 )
41 31 36 40 dvbss ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom ( 𝑆 D 𝑘 ) ⊆ dom 𝑘 )
42 41 37 sstrd ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → dom ( 𝑆 D 𝑘 ) ⊆ dom 𝐹 )
43 elpm2r ( ( ( ℂ ∈ V ∧ dom 𝐹 ∈ V ) ∧ ( ( 𝑆 D 𝑘 ) : dom ( 𝑆 D 𝑘 ) ⟶ ℂ ∧ dom ( 𝑆 D 𝑘 ) ⊆ dom 𝐹 ) ) → ( 𝑆 D 𝑘 ) ∈ ( ℂ ↑pm dom 𝐹 ) )
44 26 27 29 42 43 syl22anc ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ( 𝑆 D 𝑘 ) ∈ ( ℂ ↑pm dom 𝐹 ) )
45 25 44 eqeltrid ( ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) ∧ ( 𝑘 ∈ ( ℂ ↑pm dom 𝐹 ) ∧ 𝑛 ∈ ( ℂ ↑pm dom 𝐹 ) ) ) → ( 𝑘 ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) 𝑛 ) ∈ ( ℂ ↑pm dom 𝐹 ) )
46 1 2 16 45 seqf ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → seq 0 ( ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) , ( ℕ0 × { 𝐹 } ) ) : ℕ0 ⟶ ( ℂ ↑pm dom 𝐹 ) )
47 21 dvnfval ( ( 𝑆 ⊆ ℂ ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( 𝑆 D𝑛 𝐹 ) = seq 0 ( ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) , ( ℕ0 × { 𝐹 } ) ) )
48 30 47 sylan ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( 𝑆 D𝑛 𝐹 ) = seq 0 ( ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) , ( ℕ0 × { 𝐹 } ) ) )
49 48 feq1d ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( ( 𝑆 D𝑛 𝐹 ) : ℕ0 ⟶ ( ℂ ↑pm dom 𝐹 ) ↔ seq 0 ( ( ( 𝑥 ∈ V ↦ ( 𝑆 D 𝑥 ) ) ∘ 1st ) , ( ℕ0 × { 𝐹 } ) ) : ℕ0 ⟶ ( ℂ ↑pm dom 𝐹 ) ) )
50 46 49 mpbird ( ( 𝑆 ∈ { ℝ , ℂ } ∧ 𝐹 ∈ ( ℂ ↑pm 𝑆 ) ) → ( 𝑆 D𝑛 𝐹 ) : ℕ0 ⟶ ( ℂ ↑pm dom 𝐹 ) )