Singular

D.5.5.9 createBO

Usage:

createBO(J[,W][,E]);
J,W = ideals
E = list

Assume:

J = ideal containing W ( W = 0 if not specified)
E = list of smooth hypersurfaces (e.g. exceptional divisors)

Return:

list BO representing a basic object :
BO[1] ideal W, if W has been specified; ideal(0) otherwise BO[2] ideal J
BO[3] intvec
BO[4] the list E of exceptional divisors if specified; empty list otherwise
BO[5] an ideal defining the identity map
BO[6] an intvec
BO[7] intvec
BO[8] a matrix
entries 3,5,6,7,8 are initialized appropriately for use of CenterBO and blowUpBO

LIB "resolve.lib";
ring R=0,(x,y,z),dp;
ideal J=x2-y3;
createBO(J,ideal(z));
==> [1]:
==>    _[1]=z
==> [2]:
==>    _[1]=-y3+x2
==> [3]:
==>    0
==> [4]:
==>    empty list
==> [5]:
==>    _[1]=x
==>    _[2]=y
==>    _[3]=z
==> [6]:
==>    0
==> [7]:
==>    -1
==> [8]:
==>    _[1,1]=0