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5.1.74 minres

Syntax:

minres ( list_expression )

Type:

list

Syntax:

minres ( resolution_expression )

Type:

resolution

Purpose:

minimizes a free resolution of an ideal or module given by the list_expression, resp. resolution_expression.

Example:
 
  ring r1=32003,(x,y),dp;
  ideal i=x5+xy4,x3+x2y+xy2+y3;
  resolution rs=lres(i,0);
  rs;
→   1       2       1       
→ r1 <--  r1 <--  r1
→ 
→ 0       1       2       
→ resolution not minimized yet
→ 
  list(rs);
→ [1]:
→    _[1]=x3+x2y+xy2+y3
→    _[2]=xy4
→    _[3]=y7
→ [2]:
→    _[1]=-y4*gen(1)+x2*gen(2)+xy*gen(2)+y2*gen(2)+gen(3)
→    _[2]=-y3*gen(2)+x*gen(3)
  minres(rs);
→   1       2       1       
→ r1 <--  r1 <--  r1
→ 
→ 0       1       2       
→ 
  list(rs);
→ [1]:
→    _[1]=x3+x2y+xy2+y3
→    _[2]=xy4
→ [2]:
→    _[1]=xy4*gen(1)-x3*gen(2)-x2y*gen(2)-xy2*gen(2)-y3*gen(2)

See mres; res; sres.


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