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7.5.20.0. ncRelations
Procedure from library nctools.lib (see nctools_lib).
- Usage:
- ncRelations(r); r a ring
- Return:
- list L with two elements, both elements are of type matrix:
L[1] = matrix of coefficients C,
L[2] = matrix of polynomials D
- Purpose:
- recover the noncommutative relations via matrices C and D from
a noncommutative ring
Example:
| LIB "nctools.lib";
ring r = 0,(x,y,z),dp;
matrix C[3][3]=0,1,2,0,0,-1,0,0,0;
print(C);
==> 0,1,2,
==> 0,0,-1,
==> 0,0,0
matrix D[3][3]=0,1,2y,0,0,-2x+y+1;
print(D);
==> 0,1,2y,
==> 0,0,-2x+y+1,
==> 0,0,0
def S=nc_algebra(C,D);setring S; S;
==> // coefficients: QQ
==> // number of vars : 3
==> // block 1 : ordering dp
==> // : names x y z
==> // block 2 : ordering C
==> // noncommutative relations:
==> // yx=xy+1
==> // zx=2xz+2y
==> // zy=-yz-2x+y+1
def l=ncRelations(S);
print (l[1]);
==> 0,1,2,
==> 0,0,-1,
==> 0,0,0
print (l[2]);
==> 0,1,2y,
==> 0,0,-2x+y+1,
==> 0,0,0
| See also:
G-algebras;
ringlist.
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