Definition df-mdet 21734

Description: Determinant of a square matrix. This definition is based on Leibniz' Formula (see mdetleib 21736). The properties of the axiomatic definition of a determinant according to [Weierstrass] p. 272 are derived from this definition as theorems: "The determinant function is the unique multilinear, alternating and normalized function from the algebra of square matrices of the same dimension over a commutative ring to this ring". Functionality is shown by mdetf 21744. Multilineary means "linear for each row" - the additivity is shown by mdetrlin 21751, the homogeneity by mdetrsca 21752. Furthermore, it is shown that the determinant function is alternating (see mdetralt 21757) and normalized (see mdet1 21750). Finally, uniqueness is shown by mdetuni 21771. As a consequence, the "determinant of a square matrix" is the function value of the determinant function for this square matrix, see mdetleib 21736. (Contributed by Stefan O'Rear, 9-Sep-2015.) (Revised by SO, 10-Jul-2018.)

Assertion

Ref	Expression
df-mdet	⊢ maDet = (𝑛 ∈ V, 𝑟 ∈ V ↦ (𝑚 ∈ (Base‘(𝑛 Mat 𝑟)) ↦ (𝑟 Σg (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))))))))

Distinct variable group:   𝑛,𝑟,𝑚,𝑝,𝑥

Detailed syntax breakdown of Definition df-mdet

Step	Hyp	Ref	Expression
1		cmdat 21733	. 2 class maDet
2		vn	. . 3 setvar 𝑛
3		vr	. . 3 setvar 𝑟
4		cvv 3432	. . 3 class V
5		vm	. . . 4 setvar 𝑚
6	2	cv 1538	. . . . . 6 class 𝑛
7	3	cv 1538	. . . . . 6 class 𝑟
8		cmat 21554	. . . . . 6 class Mat
9	6, 7, 8	co 7275	. . . . 5 class (𝑛 Mat 𝑟)
10		cbs 16912	. . . . 5 class Base
11	9, 10	cfv 6433	. . . 4 class (Base‘(𝑛 Mat 𝑟))
12		vp	. . . . . 6 setvar 𝑝
13		csymg 18974	. . . . . . . 8 class SymGrp
14	6, 13	cfv 6433	. . . . . . 7 class (SymGrp‘𝑛)
15	14, 10	cfv 6433	. . . . . 6 class (Base‘(SymGrp‘𝑛))
16	12	cv 1538	. . . . . . . 8 class 𝑝
17		czrh 20701	. . . . . . . . . 10 class ℤRHom
18	7, 17	cfv 6433	. . . . . . . . 9 class (ℤRHom‘𝑟)
19		cpsgn 19097	. . . . . . . . . 10 class pmSgn
20	6, 19	cfv 6433	. . . . . . . . 9 class (pmSgn‘𝑛)
21	18, 20	ccom 5593	. . . . . . . 8 class ((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))
22	16, 21	cfv 6433	. . . . . . 7 class (((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)
23		cmgp 19720	. . . . . . . . 9 class mulGrp
24	7, 23	cfv 6433	. . . . . . . 8 class (mulGrp‘𝑟)
25		vx	. . . . . . . . 9 setvar 𝑥
26	25	cv 1538	. . . . . . . . . . 11 class 𝑥
27	26, 16	cfv 6433	. . . . . . . . . 10 class (𝑝‘𝑥)
28	5	cv 1538	. . . . . . . . . 10 class 𝑚
29	27, 26, 28	co 7275	. . . . . . . . 9 class ((𝑝‘𝑥)𝑚𝑥)
30	25, 6, 29	cmpt 5157	. . . . . . . 8 class (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))
31		cgsu 17151	. . . . . . . 8 class Σg
32	24, 30, 31	co 7275	. . . . . . 7 class ((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥)))
33		cmulr 16963	. . . . . . . 8 class .r
34	7, 33	cfv 6433	. . . . . . 7 class (.r‘𝑟)
35	22, 32, 34	co 7275	. . . . . 6 class ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))))
36	12, 15, 35	cmpt 5157	. . . . 5 class (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥)))))
37	7, 36, 31	co 7275	. . . 4 class (𝑟 Σg (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))))))
38	5, 11, 37	cmpt 5157	. . 3 class (𝑚 ∈ (Base‘(𝑛 Mat 𝑟)) ↦ (𝑟 Σg (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥)))))))
39	2, 3, 4, 4, 38	cmpo 7277	. 2 class (𝑛 ∈ V, 𝑟 ∈ V ↦ (𝑚 ∈ (Base‘(𝑛 Mat 𝑟)) ↦ (𝑟 Σg (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))))))))
40	1, 39	wceq 1539	1 wff maDet = (𝑛 ∈ V, 𝑟 ∈ V ↦ (𝑚 ∈ (Base‘(𝑛 Mat 𝑟)) ↦ (𝑟 Σg (𝑝 ∈ (Base‘(SymGrp‘𝑛)) ↦ ((((ℤRHom‘𝑟) ∘ (pmSgn‘𝑛))‘𝑝)(.r‘𝑟)((mulGrp‘𝑟) Σg (𝑥 ∈ 𝑛 ↦ ((𝑝‘𝑥)𝑚𝑥))))))))

This definition is referenced by:  mdetfval  21735