Metamath Proof Explorer


Definition df-crossp

Description: Define the cross product of two 3-dimensional real coordinate vectors. Vectors are represented as functions on ( 1 ... 3 ) . (Contributed by Jiamin Zhao, 31-Jul-2026)

Ref Expression
Assertion df-crossp Could not format assertion : No typesetting found for |- crossp = ( u e. ( RR ^m ( 1 ... 3 ) ) , v e. ( RR ^m ( 1 ... 3 ) ) |-> ( k e. ( 1 ... 3 ) |-> if ( k = 1 , ( ( ( u ` 2 ) x. ( v ` 3 ) ) - ( ( u ` 3 ) x. ( v ` 2 ) ) ) , if ( k = 2 , ( ( ( u ` 3 ) x. ( v ` 1 ) ) - ( ( u ` 1 ) x. ( v ` 3 ) ) ) , ( ( ( u ` 1 ) x. ( v ` 2 ) ) - ( ( u ` 2 ) x. ( v ` 1 ) ) ) ) ) ) ) with typecode |-

Detailed syntax breakdown

Step Hyp Ref Expression
0 ccrossp Could not format crossp : No typesetting found for class crossp with typecode class
1 vu setvar u
2 cr class ℝ
3 cmap class ↑ 𝑚
4 c1 class 1
5 cfz class …
6 c3 class 3
7 4 6 5 co class 1 … 3
8 2 7 3 co class ℝ 1 … 3
9 vv setvar v
10 vk setvar k
11 10 cv setvar k
12 11 4 wceq wff k = 1
13 1 cv setvar u
14 c2 class 2
15 14 13 cfv class u ⁡ 2
16 cmul class ×
17 9 cv setvar v
18 6 17 cfv class v ⁡ 3
19 15 18 16 co class u ⁡ 2 ⁢ v ⁡ 3
20 cmin class −
21 6 13 cfv class u ⁡ 3
22 14 17 cfv class v ⁡ 2
23 21 22 16 co class u ⁡ 3 ⁢ v ⁡ 2
24 19 23 20 co class u ⁡ 2 ⁢ v ⁡ 3 − u ⁡ 3 ⁢ v ⁡ 2
25 11 14 wceq wff k = 2
26 4 17 cfv class v ⁡ 1
27 21 26 16 co class u ⁡ 3 ⁢ v ⁡ 1
28 4 13 cfv class u ⁡ 1
29 28 18 16 co class u ⁡ 1 ⁢ v ⁡ 3
30 27 29 20 co class u ⁡ 3 ⁢ v ⁡ 1 − u ⁡ 1 ⁢ v ⁡ 3
31 28 22 16 co class u ⁡ 1 ⁢ v ⁡ 2
32 15 26 16 co class u ⁡ 2 ⁢ v ⁡ 1
33 31 32 20 co class u ⁡ 1 ⁢ v ⁡ 2 − u ⁡ 2 ⁢ v ⁡ 1
34 25 30 33 cif class if k = 2 u ⁡ 3 ⁢ v ⁡ 1 − u ⁡ 1 ⁢ v ⁡ 3 u ⁡ 1 ⁢ v ⁡ 2 − u ⁡ 2 ⁢ v ⁡ 1
35 12 24 34 cif class if k = 1 u ⁡ 2 ⁢ v ⁡ 3 − u ⁡ 3 ⁢ v ⁡ 2 if k = 2 u ⁡ 3 ⁢ v ⁡ 1 − u ⁡ 1 ⁢ v ⁡ 3 u ⁡ 1 ⁢ v ⁡ 2 − u ⁡ 2 ⁢ v ⁡ 1
36 10 7 35 cmpt class k ∈ 1 … 3 ⟼ if k = 1 u ⁡ 2 ⁢ v ⁡ 3 − u ⁡ 3 ⁢ v ⁡ 2 if k = 2 u ⁡ 3 ⁢ v ⁡ 1 − u ⁡ 1 ⁢ v ⁡ 3 u ⁡ 1 ⁢ v ⁡ 2 − u ⁡ 2 ⁢ v ⁡ 1
37 1 9 8 8 36 cmpo class u ∈ ℝ 1 … 3 , v ∈ ℝ 1 … 3 ⟼ k ∈ 1 … 3 ⟼ if k = 1 u ⁡ 2 ⁢ v ⁡ 3 − u ⁡ 3 ⁢ v ⁡ 2 if k = 2 u ⁡ 3 ⁢ v ⁡ 1 − u ⁡ 1 ⁢ v ⁡ 3 u ⁡ 1 ⁢ v ⁡ 2 − u ⁡ 2 ⁢ v ⁡ 1
38 0 37 wceq Could not format crossp = ( u e. ( RR ^m ( 1 ... 3 ) ) , v e. ( RR ^m ( 1 ... 3 ) ) |-> ( k e. ( 1 ... 3 ) |-> if ( k = 1 , ( ( ( u ` 2 ) x. ( v ` 3 ) ) - ( ( u ` 3 ) x. ( v ` 2 ) ) ) , if ( k = 2 , ( ( ( u ` 3 ) x. ( v ` 1 ) ) - ( ( u ` 1 ) x. ( v ` 3 ) ) ) , ( ( ( u ` 1 ) x. ( v ` 2 ) ) - ( ( u ` 2 ) x. ( v ` 1 ) ) ) ) ) ) ) : No typesetting found for wff crossp = ( u e. ( RR ^m ( 1 ... 3 ) ) , v e. ( RR ^m ( 1 ... 3 ) ) |-> ( k e. ( 1 ... 3 ) |-> if ( k = 1 , ( ( ( u ` 2 ) x. ( v ` 3 ) ) - ( ( u ` 3 ) x. ( v ` 2 ) ) ) , if ( k = 2 , ( ( ( u ` 3 ) x. ( v ` 1 ) ) - ( ( u ` 1 ) x. ( v ` 3 ) ) ) , ( ( ( u ` 1 ) x. ( v ` 2 ) ) - ( ( u ` 2 ) x. ( v ` 1 ) ) ) ) ) ) ) with typecode wff