Metamath Proof Explorer


Theorem 3factsumint4

Description: Move constants out of integrals or sums and/or commute sum and integral. (Contributed by metakunt, 26-Apr-2024)

Ref Expression
Hypotheses 3factsumint4.1 ⊢ ( 𝜑 → 𝐵 ∈ Fin )
3factsumint4.2 ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐹 ∈ ℂ )
3factsumint4.3 ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐵 ) → 𝐺 ∈ ℂ )
3factsumint4.4 ⊢ ( ( 𝜑 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑘 ∈ 𝐵 ) ) → 𝐻 ∈ ℂ )
Assertion 3factsumint4 ( 𝜑 → ∫ 𝐴 Σ 𝑘 ∈ 𝐵 ( 𝐹 · ( 𝐺 · 𝐻 ) ) d 𝑥 = ∫ 𝐴 ( 𝐹 · Σ 𝑘 ∈ 𝐵 ( 𝐺 · 𝐻 ) ) d 𝑥 )

Proof

Step Hyp Ref Expression
1 3factsumint4.1 ⊢ ( 𝜑 → 𝐵 ∈ Fin )
2 3factsumint4.2 ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐹 ∈ ℂ )
3 3factsumint4.3 ⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐵 ) → 𝐺 ∈ ℂ )
4 3factsumint4.4 ⊢ ( ( 𝜑 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑘 ∈ 𝐵 ) ) → 𝐻 ∈ ℂ )
5 1 adantr ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → 𝐵 ∈ Fin )
6 3 adantlr ⊢ ( ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) → 𝐺 ∈ ℂ )
7 anass ⊢ ( ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) ↔ ( 𝜑 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑘 ∈ 𝐵 ) ) )
8 7 bicomi ⊢ ( ( 𝜑 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑘 ∈ 𝐵 ) ) ↔ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) )
9 8 imbi1i ⊢ ( ( ( 𝜑 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑘 ∈ 𝐵 ) ) → 𝐻 ∈ ℂ ) ↔ ( ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) → 𝐻 ∈ ℂ ) )
10 4 9 mpbi ⊢ ( ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) → 𝐻 ∈ ℂ )
11 6 10 mulcld ⊢ ( ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) ∧ 𝑘 ∈ 𝐵 ) → ( 𝐺 · 𝐻 ) ∈ ℂ )
12 5 2 11 fsummulc2 ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → ( 𝐹 · Σ 𝑘 ∈ 𝐵 ( 𝐺 · 𝐻 ) ) = Σ 𝑘 ∈ 𝐵 ( 𝐹 · ( 𝐺 · 𝐻 ) ) )
13 12 eqcomd ⊢ ( ( 𝜑 ∧ 𝑥 ∈ 𝐴 ) → Σ 𝑘 ∈ 𝐵 ( 𝐹 · ( 𝐺 · 𝐻 ) ) = ( 𝐹 · Σ 𝑘 ∈ 𝐵 ( 𝐺 · 𝐻 ) ) )
14 13 itgeq2dv ⊢ ( 𝜑 → ∫ 𝐴 Σ 𝑘 ∈ 𝐵 ( 𝐹 · ( 𝐺 · 𝐻 ) ) d 𝑥 = ∫ 𝐴 ( 𝐹 · Σ 𝑘 ∈ 𝐵 ( 𝐺 · 𝐻 ) ) d 𝑥 )