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D.4.2.3 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 occurring 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) block ordering
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] |