set P = Polynom-Ring p;
set C = { q where q is Polynomial of F : deg q < deg p } ;
H0: { q where q is Polynomial of F : deg q < deg p } = the carrier of (Polynom-Ring p) by defprfp;
H2: 1. (Polynom-Ring p) = 1_. F by defprfp;
reconsider p1 = p as Polynomial of F ;
now :: thesis: for x, y, z being Element of (Polynom-Ring p) holds x * (y * z) = (x * y) * z
let x, y, z be Element of (Polynom-Ring p); :: thesis: x * (y * z) = (x * y) * z
x in the carrier of (Polynom-Ring p) ;
then x in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider q being Polynomial of F such that
A1: ( x = q & deg q < deg p ) ;
y in the carrier of (Polynom-Ring p) ;
then y in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider r being Polynomial of F such that
A2: ( y = r & deg r < deg p ) ;
z in the carrier of (Polynom-Ring p) ;
then z in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider u being Polynomial of F such that
A3: ( z = u & deg u < deg p ) ;
A3a: ( [x,y] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [y,z] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A3b: ( [(x * y),z] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [x,(y * z)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A4: x * y = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,y) by H0, defprfp
.= (poly_mult_mod p) . (x,y) by A3a, FUNCT_1:49
.= (q *' r) mod p1 by A1, A2, defpmm ;
A5: y * z = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (y,z) by H0, defprfp
.= (poly_mult_mod p) . (y,z) by A3a, FUNCT_1:49
.= (r *' u) mod p1 by A3, A2, defpmm ;
A6: (x * y) * z = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . ((x * y),z) by H0, defprfp
.= (poly_mult_mod p) . ((x * y),z) by A3b, FUNCT_1:49
.= (((q *' r) mod p1) *' u) mod p1 by A3, A4, defpmm
.= ((q *' r) *' u) mod p1 by div3 ;
thus x * (y * z) = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,(y * z)) by H0, defprfp
.= (poly_mult_mod p) . (x,(y * z)) by A3b, FUNCT_1:49
.= (((r *' u) mod p1) *' q) mod p1 by A1, A5, defpmm
.= ((r *' u) *' q) mod p1 by div3
.= (x * y) * z by A6, POLYNOM3:33 ; :: thesis: verum
end;
hence Polynom-Ring p is associative by GROUP_1:def 3; :: thesis: ( Polynom-Ring p is well-unital & Polynom-Ring p is distributive )
now :: thesis: for x being Element of (Polynom-Ring p) holds
( x * (1. (Polynom-Ring p)) = x & (1. (Polynom-Ring p)) * x = x )
let x be Element of (Polynom-Ring p); :: thesis: ( x * (1. (Polynom-Ring p)) = x & (1. (Polynom-Ring p)) * x = x )
x in the carrier of (Polynom-Ring p) ;
then x in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider q being Polynomial of F such that
A1: ( x = q & deg q < deg p ) ;
A3a: ( [x,(1. (Polynom-Ring p))] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [(1. (Polynom-Ring p)),x] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
thus x * (1. (Polynom-Ring p)) = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,(1. (Polynom-Ring p))) by H0, defprfp
.= (poly_mult_mod p) . (x,(1. (Polynom-Ring p))) by A3a, FUNCT_1:49
.= (q *' (1_. F)) mod p1 by H2, A1, defpmm
.= q mod p1 by POLYNOM3:35
.= x by A1, div1 ; :: thesis: (1. (Polynom-Ring p)) * x = x
thus (1. (Polynom-Ring p)) * x = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . ((1. (Polynom-Ring p)),x) by H0, defprfp
.= (poly_mult_mod p) . ((1. (Polynom-Ring p)),x) by A3a, FUNCT_1:49
.= ((1_. F) *' q) mod p1 by H2, A1, defpmm
.= q mod p1 by POLYNOM3:35
.= x by A1, div1 ; :: thesis: verum
end;
hence Polynom-Ring p is well-unital by VECTSP_1:def 6; :: thesis: Polynom-Ring p is distributive
now :: thesis: for x, y, z being Element of (Polynom-Ring p) holds
( (x * y) + (x * z) = x * (y + z) & (y * x) + (z * x) = (y + z) * x )
let x, y, z be Element of (Polynom-Ring p); :: thesis: ( (x * y) + (x * z) = x * (y + z) & (y * x) + (z * x) = (y + z) * x )
x in the carrier of (Polynom-Ring p) ;
then x in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider q being Polynomial of F such that
A1: ( x = q & deg q < deg p ) ;
y in the carrier of (Polynom-Ring p) ;
then y in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider r being Polynomial of F such that
A2: ( y = r & deg r < deg p ) ;
z in the carrier of (Polynom-Ring p) ;
then z in { q where q is Polynomial of F : deg q < deg p } by defprfp;
then consider u being Polynomial of F such that
A3: ( z = u & deg u < deg p ) ;
reconsider q1 = q, r1 = r, u1 = u as Element of (Polynom-Ring F) by POLYNOM3:def 10;
A3a: ( [x,y] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [x,z] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [y,z] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A3b: ( [(x * y),(x * z)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [x,(y * z)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [x,(y + z)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A4: y + z = ( the addF of (Polynom-Ring F) || { q where q is Polynomial of F : deg q < deg p } ) . (y,z) by H0, defprfp
.= r1 + u1 by A2, A3, A3a, FUNCT_1:49
.= r + u by POLYNOM3:def 10 ;
A5: x * (y + z) = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,(y + z)) by H0, defprfp
.= (poly_mult_mod p) . (x,(y + z)) by A3b, FUNCT_1:49
.= (q *' (r + u)) mod p1 by A1, A4, defpmm ;
A6: x * y = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,y) by H0, defprfp
.= (poly_mult_mod p) . (x,y) by A3a, FUNCT_1:49
.= (q *' r) mod p1 by A1, A2, defpmm ;
A7: x * z = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (x,z) by H0, defprfp
.= (poly_mult_mod p) . (x,z) by A3a, FUNCT_1:49
.= (q *' u) mod p1 by A1, A3, defpmm ;
reconsider s = (q *' r) mod p1 as Element of (Polynom-Ring F) by POLYNOM3:def 10;
reconsider t = (q *' u) mod p1 as Element of (Polynom-Ring F) by POLYNOM3:def 10;
thus (x * y) + (x * z) = ( the addF of (Polynom-Ring F) || { q where q is Polynomial of F : deg q < deg p } ) . ((x * y),(x * z)) by H0, defprfp
.= s + t by A6, A7, A3b, FUNCT_1:49
.= ((q *' r) mod p1) + ((q *' u) mod p1) by POLYNOM3:def 10
.= ((q *' r) + (q *' u)) mod p1 by div4
.= x * (y + z) by A5, POLYNOM3:31 ; :: thesis: (y * x) + (z * x) = (y + z) * x
A3a: ( [y,x] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [z,x] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [y,z] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A3b: ( [(y * x),(z * x)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [x,(y * z)] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] & [(y + z),x] in [: { q where q is Polynomial of F : deg q < deg p } , { q where q is Polynomial of F : deg q < deg p } :] ) by H0, ZFMISC_1:def 2;
A4: y + z = ( the addF of (Polynom-Ring F) || { q where q is Polynomial of F : deg q < deg p } ) . (y,z) by H0, defprfp
.= r1 + u1 by A2, A3, A3a, FUNCT_1:49
.= r + u by POLYNOM3:def 10 ;
A5: (y + z) * x = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . ((y + z),x) by H0, defprfp
.= (poly_mult_mod p) . ((y + z),x) by A3b, FUNCT_1:49
.= ((r + u) *' q) mod p1 by A1, A4, defpmm ;
A6: y * x = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (y,x) by H0, defprfp
.= (poly_mult_mod p) . (y,x) by A3a, FUNCT_1:49
.= (r *' q) mod p1 by A1, A2, defpmm ;
A7: z * x = ((poly_mult_mod p) || { q where q is Polynomial of F : deg q < deg p } ) . (z,x) by H0, defprfp
.= (poly_mult_mod p) . (z,x) by A3a, FUNCT_1:49
.= (u *' q) mod p1 by A1, A3, defpmm ;
reconsider s = (r *' q) mod p1 as Element of (Polynom-Ring F) by POLYNOM3:def 10;
reconsider t = (u *' q) mod p1 as Element of (Polynom-Ring F) by POLYNOM3:def 10;
thus (y * x) + (z * x) = ( the addF of (Polynom-Ring F) || { q where q is Polynomial of F : deg q < deg p } ) . ((y * x),(z * x)) by H0, defprfp
.= s + t by A6, A7, A3b, FUNCT_1:49
.= ((q *' r) mod p1) + ((q *' u) mod p1) by POLYNOM3:def 10
.= ((q *' r) + (q *' u)) mod p1 by div4
.= (y + z) * x by A5, POLYNOM3:31 ; :: thesis: verum
end;
hence Polynom-Ring p is distributive by VECTSP_1:def 7; :: thesis: verum