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 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 0 1 n
5 fvex 1 N V
6 3 4 5 fvmpt N 0 𝔼 hil N = 1 N
7 1 6 eqtrid N 0 E = 1 N