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D.2.4.14 locusdg

Procedure from library grobcov.lib (see grobcov_lib).

Usage:
locusdg(list L)
Calling sequence:
locusdg(locus(grobcov(S))).

Return:
The output is the list of the "Relevant" components of the locus in Dynamic Geometry [C1,..,C:m], where C_i= [p_i,[p_i1,..p_is_i], "Relevant", level_i]
The "Relevant" components are the "Normal" and "Accumulation" components of the locus. (See help for locus).

Example:
 
LIB "grobcov.lib";
if(defined(R)){kill R;};
ring R=(0,a,b),(x,y),dp;
short=0;
// Concoid
ideal S96=x^2+y^2-4,(b-2)*x-a*y+2*a,(a-x)^2+(b-y)^2-1;
S96;
==> S96[1]=x^2+y^2-4
==> S96[2]=(b-2)*x+(-a)*y+(2*a)
==> S96[3]=x^2+y^2+(-2*a)*x+(-2*b)*y+(a^2+b^2-1)
locus(grobcov(S96));
==> [1]:
==>    [1]:
==>       _[1]=(a^4+2*a^2*b^2-9*a^2+b^4-9*b^2+4*b+12)
==>    [2]:
==>       [1]:
==>          _[1]=1
==>    [3]:
==>       Normal
==>    [4]:
==>       1
==> [2]:
==>    [1]:
==>       _[1]=(a^2+b^2-4*b+3)
==>    [2]:
==>       [1]:
==>          _[1]=1
==>    [3]:
==>       [1]:
==>          Special
==>       [2]:
==>          y-2,x
==>    [4]:
==>       1
locusdg(locus(grobcov(S96)));
==> [1]:
==>    [1]:
==>       _[1]=(a^4+2*a^2*b^2-9*a^2+b^4-9*b^2+4*b+12)
==>    [2]:
==>       [1]:
==>          _[1]=1
==>    [3]:
==>       Relevant
==>    [4]:
==>       1