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D.4.3.3 elim1
Procedure from library elim.lib (see elim_lib).
- Usage:
- elim1(id,p); id ideal/module, p product of vars to be eliminated
- Return:
- ideal/module obtained from id by eliminating vars occuring in poly
- Note:
- no special monomial ordering is required, result is a SB with
respect to ordering dp (resp. ls) if the first var not to be
eliminated belongs to a -p (resp. -s) blockordering
This proc uses 'execute' or calls a procedure using 'execute'.
Example:
| LIB "elim.lib";
ring r=0,(x,y,t,s,z),dp;
ideal i=x-t,y-t2,z-t3,s-x+y3;
elim1(i,ts);
==> _[1]=y2-xz
==> _[2]=xy-z
==> _[3]=x2-y
module m=i*gen(1)+i*gen(2);
m=elim1(m,st); show(m);
==> // module, 6 generator(s)
==> [y2-xz]
==> [0,y2-xz]
==> [xy-z]
==> [0,xy-z]
==> [x2-y]
==> [0,x2-y]
| elim, eliminate
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