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Database
BASIC ALGEBRAIC STRUCTURES
Generalized pre-Hilbert and Hilbert spaces
Definition and basic properties
df-ipf
Metamath Proof Explorer
Description: Define the inner product function. Usually we will use .i directly
instead of .if , and they have the same behavior in most cases. The
main advantage of .if is that it is a guaranteed function
( ipffn ), while .i only has closure ( ipcl ). (Contributed by Mario Carneiro , 12-Aug-2015)
Ref
Expression
Assertion
df-ipf
⊢ ⋅ if = g ∈ V ⟼ x ∈ Base g , y ∈ Base g ⟼ x ⋅ 𝑖 ⁡ g y
Detailed syntax breakdown
Step
Hyp
Ref
Expression
0
cipf
class ⋅ if
1
vg
setvar g
2
cvv
class V
3
vx
setvar x
4
cbs
class Base
5
1
cv
setvar g
6
5 4
cfv
class Base g
7
vy
setvar y
8
3
cv
setvar x
9
cip
class ⋅ 𝑖
10
5 9
cfv
class ⋅ 𝑖 ⁡ g
11
7
cv
setvar y
12
8 11 10
co
class x ⋅ 𝑖 ⁡ g y
13
3 7 6 6 12
cmpo
class x ∈ Base g , y ∈ Base g ⟼ x ⋅ 𝑖 ⁡ g y
14
1 2 13
cmpt
class g ∈ V ⟼ x ∈ Base g , y ∈ Base g ⟼ x ⋅ 𝑖 ⁡ g y
15
0 14
wceq
wff ⋅ if = g ∈ V ⟼ x ∈ Base g , y ∈ Base g ⟼ x ⋅ 𝑖 ⁡ g y