Database
REAL AND COMPLEX NUMBERS
Elementary limits and convergence
Finite and infinite products
Finite products
fprodreclf
Metamath Proof Explorer
Description: Closure of a finite product of real numbers. A version of fprodrecl using bound-variable hypotheses instead of distinct variable conditions.
(Contributed by Glauco Siliprandi , 5-Apr-2020)
Ref
Expression
Hypotheses
fprodreclf.kph
⊢ Ⅎ 𝑘 𝜑
fprodcl.a
⊢ ( 𝜑 → 𝐴 ∈ Fin )
fprodrecl.b
⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐴 ) → 𝐵 ∈ ℝ )
Assertion
fprodreclf
⊢ ( 𝜑 → ∏ 𝑘 ∈ 𝐴 𝐵 ∈ ℝ )
Proof
Step
Hyp
Ref
Expression
1
fprodreclf.kph
⊢ Ⅎ 𝑘 𝜑
2
fprodcl.a
⊢ ( 𝜑 → 𝐴 ∈ Fin )
3
fprodrecl.b
⊢ ( ( 𝜑 ∧ 𝑘 ∈ 𝐴 ) → 𝐵 ∈ ℝ )
4
ax-resscn
⊢ ℝ ⊆ ℂ
5
4
a1i
⊢ ( 𝜑 → ℝ ⊆ ℂ )
6
remulcl
⊢ ( ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) → ( 𝑥 · 𝑦 ) ∈ ℝ )
7
6
adantl
⊢ ( ( 𝜑 ∧ ( 𝑥 ∈ ℝ ∧ 𝑦 ∈ ℝ ) ) → ( 𝑥 · 𝑦 ) ∈ ℝ )
8
1red
⊢ ( 𝜑 → 1 ∈ ℝ )
9
1 5 7 2 3 8
fprodcllemf
⊢ ( 𝜑 → ∏ 𝑘 ∈ 𝐴 𝐵 ∈ ℝ )