|  |  D.10.1.7 AGcode_Omega Procedure from librarybrnoeth.lib(see  brnoeth_lib).
 
Example:Usage:
AGcode_Omega( G, D, EC ); G,D intvec, EC a list
Return:
a generator matrix for the residual AG code defined by the
divisors G and D.
Note:
The procedure must be called within the ring EC[1][4],
where EC is the output of extcurve(d)(or within
the ring EC[1][2] if d=1).The entry i in the intvec D refers to the i-th rational
place in EC[1][5] (i.e., to POINTS[i], etc., see  extcurve).
 The intvec G represents a rational divisor (see  BrillNoether
for more details).
 The code computes the residues of a vector space basis of
 
 at the rational places given by D. 
Warnings:
G should satisfy 
 , which is
not checked by the algorithm. G and D should have disjoint supports (checked by the algorithm).
 
 See also:
 AGcode_L;
 Adj_div;
 BrillNoether;
 extcurve.|  | LIB "brnoeth.lib";
int plevel=printlevel;
printlevel=-1;
ring s=2,(x,y),lp;
list HC=Adj_div(x3+y2+y);
==> The genus of the curve is 1
HC=NSplaces(1..2,HC);
HC=extcurve(2,HC);
==> Total number of rational places : NrRatPl = 9
def ER=HC[1][4];
setring ER;
intvec G=5;      // the rational divisor G = 5*HC[3][1]
intvec D=2..9;   // D = sum of the rational places no. 2..9 over F_4
// let us construct the corresponding residual AG code :
matrix C=AGcode_Omega(G,D,HC);
==> Vector basis successfully computed 
// here is a linear code of type [8,3,>=5] over F_4
print(C);
==> 1,    0,    (a),(a+1),1,1,0,0,
==> (a+1),(a),  1,  0,    1,0,1,0,
==> (a+1),(a+1),(a),(a),  1,0,0,1 
printlevel=plevel;
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