Metamath Proof Explorer


Definition df-hnorm

Description: Define the function for the norm of a vector of Hilbert space. See normval for its value and normcl for its closure. Theorems norm-i-i , norm-ii-i , and norm-iii-i show it has the expected properties of a norm. In the literature, the norm of A is usually written "|| A ||", but we use function notation to take advantage of our existing theorems about functions. Definition of norm in Beran p. 96. (Contributed by NM, 6-Jun-2008) (New usage is discouraged.)

Ref Expression
Assertion df-hnorm norm = ( 𝑥 ∈ dom dom ·ih ↦ ( √ ‘ ( 𝑥 ·ih 𝑥 ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cno norm
1 vx 𝑥
2 csp ·ih
3 2 cdm dom ·ih
4 3 cdm dom dom ·ih
5 csqrt
6 1 cv 𝑥
7 6 6 2 co ( 𝑥 ·ih 𝑥 )
8 7 5 cfv ( √ ‘ ( 𝑥 ·ih 𝑥 ) )
9 1 4 8 cmpt ( 𝑥 ∈ dom dom ·ih ↦ ( √ ‘ ( 𝑥 ·ih 𝑥 ) ) )
10 0 9 wceq norm = ( 𝑥 ∈ dom dom ·ih ↦ ( √ ‘ ( 𝑥 ·ih 𝑥 ) ) )