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D.4.2.2 elim
Procedure from library elim.lib (see elim_lib).
- Usage:
elim(id,n,m); id ideal/module, n,m integers
- Returns:
ideal/module obtained from id by eliminating variables n..m
- 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) block ordering
This proc uses ’execute’ or calls a procedure using ’execute’.
Example:
LIB "elim.lib"; ring r=0,(x,y,u,v,w),dp; ideal i=x-u,y-u2,w-u3,v-x+y3; elim(i,3,4); → _[1]=y2-xw → _[2]=xy-w → _[3]=x2-y module m=i*gen(1)+i*gen(2); m=elim(m,3,4);show(m); → // module, 6 generator(s) → [y2-xw] → [0,y2-xw] → [xy-w] → [0,xy-w] → [x2-y] → [0,x2-y] |