Singular

7.7.8.0. setLetterplaceAttributes

Usage:

setLetterplaceAttributes(R, d, b); R a ring, b,d integers

Return:

ring with special attributes set

Purpose:

sets attributes for a letterplace ring:
'isLetterplaceRing' = true, 'uptodeg' = d, 'lV' = b, where
'uptodeg' stands for the degree bound,
'lV' for the number of variables in the block 0.

Note:

Activate the resulting ring by using setring

LIB "freegb.lib";
ring r = 0,(x(1),y(1),x(2),y(2),x(3),y(3),x(4),y(4)),dp;
def R = setLetterplaceAttributes(r, 4, 2); setring R;
attrib(R,"isLetterplaceRing");
==> 1
lieBracket(x(1),y(1),2);
==> -y(1)*x(2)*x(3)*x(4)+3*x(1)*y(2)*x(3)*x(4)-3*x(1)*x(2)*y(3)*x(4)+x(1)*x(2\
   )*x(3)*y(4)