Home Online Manual
Top
Back: crystallographicGroupP2GG
Forward: crystallographicGroupC2MM
FastBack:
FastForward:
Up: fpalgebras_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

7.10.2.13 crystallographicGroupCM

Procedure from library fpalgebras.lib (see fpalgebras_lib).

Usage:
crystallographicGroupCM(d); d an integer

Return:
ring

Note:
- the ring contains the ideal I, which contains the required relations - cm group with the following presentation
< x, y, t | [x, y] = t^2 = 1, t^(-1)*x*t = x*y, t^(-1)*y*t = y^(-1) > - d gives the degreebound for the Letterplace ring

Example:
 
LIB "fpalgebras.lib";
def R = crystallographicGroupCM(5); setring R;
I;
==> I[1]=y*x+x*y+1
==> I[2]=y*x+x*y+t*t
==> I[3]=t*t+1
==> I[4]=t*x*t+x*y
==> I[5]=t*y*t+Y
==> I[6]=X*x+1
==> I[7]=x*X+1
==> I[8]=Y*y+1
==> I[9]=y*Y+1