Metamath Proof Explorer


Theorem ehlval

Description: Value of the Euclidean space of dimension N . (Contributed by Thierry Arnoux, 16-Jun-2019)

Ref Expression
Hypothesis ehlval.e ⊢ E = 𝔼 hil ⁡ N
Assertion ehlval ⊢ N ∈ ℕ 0 → E = 1 … N

Proof

Step Hyp Ref Expression
1 ehlval.e ⊢ E = 𝔼 hil ⁡ N
2 oveq2 ⊢ n = N → 1 … n = 1 … N
3 2 fveq2d ⊢ n = N → 1 … n = 1 … N
4 df-ehl ⊢ 𝔼 hil = n ∈ ℕ 0 ⟼ 1 … n
5 fvex ⊢ 1 … N ∈ V
6 3 4 5 fvmpt ⊢ N ∈ ℕ 0 → 𝔼 hil ⁡ N = 1 … N
7 1 6 eqtrid ⊢ N ∈ ℕ 0 → E = 1 … N