# NCMatrix % NCGroebnerBasis -- Reduces the entries of an NCMatrix with respect to an NCGroebnerBasis

## Synopsis

• Operator: %
• Usage:
L = M % Igb
• Inputs:
• Outputs:

## Description

This command reduces the entries of an NCMatrix with respect to an NCGroebnerBasis.

 i1 : A = QQ{x,y,z} o1 = A o1 : NCPolynomialRing i2 : f = y*z + z*y - x^2 2 o2 = zy+yz-x o2 : A i3 : g = x*z + z*x - y^2 2 o3 = zx-y +xz o3 : A i4 : h = z^2 - x*y - y*x 2 o4 = z -yx-xy o4 : A i5 : I = ncIdeal {f,g,h} 2 2 2 o5 = Two-sided ideal {zy+yz-x , zx-y +xz, z -yx-xy} o5 : NCIdeal i6 : Igb = ncGroebnerBasis I --Calling Bergman for NCGB calculation. Complete! 2 2 2 o6 = y x-xy ; Lead Term = (y x, 1) 2 2 2 yx -x y; Lead Term = (yx , 1) 2 zx-y +xz; Lead Term = (zx, 1) 2 zy+yz-x ; Lead Term = (zy, 1) 2 2 z -yx-xy; Lead Term = (z , 1) o6 : NCGroebnerBasis i7 : M = ncMatrix {{x, y, z}} o7 = | x y z | o7 : NCMatrix i8 : sigma = ncMap(A,A,{y,z,x}) o8 = NCRingMap A <--- A o8 : NCRingMap i9 : N = ncMatrix {{M},{sigma M}, {sigma sigma M}} o9 = | x y z | | y z x | | z x y | o9 : NCMatrix i10 : N3 = N^3 o10 = | z^2*x+z*y*z+z*x*y+y*z*y+y^2*x+y*x*z+x*z^2+x*y^2+x^3 z^2*y+z*y*x+z*x*z+y*z^2+y^3+y*x^2+x*z*x+x*y*z+x^2*y z^3+z*y^2+z*x^2+y*z*x+y^2*z+y*x*y+x*z*y+x*y*x+x^2*z | | z^2*y+z*y*x+z*x*z+y*z^2+y^3+y*x^2+x*z*x+x*y*z+x^2*y z^3+z*y^2+z*x^2+y*z*x+y^2*z+y*x*y+x*z*y+x*y*x+x^2*z z^2*x+z*y*z+z*x*y+y*z*y+y^2*x+y*x*z+x*z^2+x*y^2+x^3 | | z^3+z*y^2+z*x^2+y*z*x+y^2*z+y*x*y+x*z*y+x*y*x+x^2*z z^2*x+z*y*z+z*x*y+y*z*y+y^2*x+y*x*z+x*z^2+x*y^2+x^3 z^2*y+z*y*x+z*x*z+y*z^2+y^3+y*x^2+x*z*x+x*y*z+x^2*y | o10 : NCMatrix i11 : N3red = N3 % Igb o11 = | -y^2*z+y^3+y*x*z-y*x*y+x*y*z+x*y^2+2*x*y*x+x^2*z+3*x^2*y y^2*z+y*x*z+2*y*x*y+x*y*z+3*x*y^2-x*y*x-x^2*z+x^2*y+x^3 2*y^2*z+y^3+y*x*y+x*y*x+2*x^2*z+x^3 | | y^2*z+y*x*z+2*y*x*y+x*y*z+3*x*y^2-x*y*x-x^2*z+x^2*y+x^3 2*y^2*z+y^3+y*x*y+x*y*x+2*x^2*z+x^3 -y^2*z+y^3+y*x*z-y*x*y+x*y*z+x*y^2+2*x*y*x+x^2*z+3*x^2*y | | 2*y^2*z+y^3+y*x*y+x*y*x+2*x^2*z+x^3 -y^2*z+y^3+y*x*z-y*x*y+x*y*z+x*y^2+2*x*y*x+x^2*z+3*x^2*y y^2*z+y*x*z+2*y*x*y+x*y*z+3*x*y^2-x*y*x-x^2*z+x^2*y+x^3 | o11 : NCMatrix