Definition df-mplcoe 14702

Description: Define the subalgebra of the power series algebra generated by the variables; this is the polynomial algebra (the set of power series with finite degree).

The index set (which has an element for each variable) is i, the coefficients are in ring r, and for each variable there is a "degree" such that the coefficient is zero for a term where the powers are all greater than those degrees. (Degree is in quotes because there is no guarantee that coefficients below that degree are nonzero, as we do not assume decidable equality for r). (Contributed by Mario Carneiro, 7-Jan-2015.) (Revised by AV, 25-Jun-2019.) (Revised by Jim Kingdon, 7-Oct-2025.)

Assertion

Ref	Expression
df-mplcoe	|- mPoly = ( i e. _V , r e. _V |-> [_ ( i mPwSer r ) / w ]_ ( w ↾s { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) } ) )

Distinct variable group:   a, b, f, i, k, r, w

Detailed syntax breakdown of Definition df-mplcoe

Step	Hyp	Ref	Expression
1		cmpl 14700	. 2 class mPoly
2		vi	. . 3 setvar i
3		vr	. . 3 setvar r
4		cvv 2801	. . 3 class _V
5		vw	. . . 4 setvar w
6	2	cv 1396	. . . . 5 class i
7	3	cv 1396	. . . . 5 class r
8		cmps 14699	. . . . 5 class mPwSer
9	6, 7, 8	co 6023	. . . 4 class ( i mPwSer r )
10	5	cv 1396	. . . . 5 class w
11		vk	. . . . . . . . . . . . 13 setvar k
12	11	cv 1396	. . . . . . . . . . . 12 class k
13		va	. . . . . . . . . . . . 13 setvar a
14	13	cv 1396	. . . . . . . . . . . 12 class a
15	12, 14	cfv 5328	. . . . . . . . . . 11 class ( a ` k )
16		vb	. . . . . . . . . . . . 13 setvar b
17	16	cv 1396	. . . . . . . . . . . 12 class b
18	12, 17	cfv 5328	. . . . . . . . . . 11 class ( b ` k )
19		clt 8219	. . . . . . . . . . 11 class <
20	15, 18, 19	wbr 4089	. . . . . . . . . 10 wff ( a ` k ) < ( b ` k )
21	20, 11, 6	wral 2509	. . . . . . . . 9 wff A. k e. i ( a ` k ) < ( b ` k )
22		vf	. . . . . . . . . . . 12 setvar f
23	22	cv 1396	. . . . . . . . . . 11 class f
24	17, 23	cfv 5328	. . . . . . . . . 10 class ( f ` b )
25		c0g 13362	. . . . . . . . . . 11 class 0g
26	7, 25	cfv 5328	. . . . . . . . . 10 class ( 0g ` r )
27	24, 26	wceq 1397	. . . . . . . . 9 wff ( f ` b ) = ( 0g ` r )
28	21, 27	wi 4	. . . . . . . 8 wff ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) )
29		cn0 9407	. . . . . . . . 9 class NN0
30		cmap 6822	. . . . . . . . 9 class ^m
31	29, 6, 30	co 6023	. . . . . . . 8 class ( NN0 ^m i )
32	28, 16, 31	wral 2509	. . . . . . 7 wff A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) )
33	32, 13, 31	wrex 2510	. . . . . 6 wff E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) )
34		cbs 13105	. . . . . . 7 class Base
35	10, 34	cfv 5328	. . . . . 6 class ( Base ` w )
36	33, 22, 35	crab 2513	. . . . 5 class { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) }
37		cress 13106	. . . . 5 class ↾s
38	10, 36, 37	co 6023	. . . 4 class ( w ↾s { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) } )
39	5, 9, 38	csb 3126	. . 3 class [_ ( i mPwSer r ) / w ]_ ( w ↾s { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) } )
40	2, 3, 4, 4, 39	cmpo 6025	. 2 class ( i e. _V , r e. _V |-> [_ ( i mPwSer r ) / w ]_ ( w ↾s { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) } ) )
41	1, 40	wceq 1397	1 wff mPoly = ( i e. _V , r e. _V |-> [_ ( i mPwSer r ) / w ]_ ( w ↾s { f e. ( Base ` w ) | E. a e. ( NN0 ^m i ) A. b e. ( NN0 ^m i ) ( A. k e. i ( a ` k ) < ( b ` k ) -> ( f ` b ) = ( 0g ` r ) ) } ) )

This definition is referenced by:  reldmmpl  14732  mplvalcoe  14733  fnmpl  14736