I am looking for quadratic forms with a given point - so I want short integer vectors which are perpendicular to
v=[XX,XY,XZ,XT,YY,YZ,YT,ZZ,ZT,TT]
for (in this case) [X,Y,Z,T]=[4423,7583,8765,3459]
This sounds like a problem with LLL written all over it, so I do
L=[[Y,-X,0,0,0,0,0,0,0,0],[0,Z,-Y,0,0,0,0,0,0,0],[0,0,T,-Z,0,0,0,0,0,0],[0,0,0,YY,-XT,0,0,0,0,0],[0,0,0,0,Z,-Y,0,0,0,0],[0,0,0,0,0,T,-Z,0,0,0],[0,0,0,0,0,0,ZZ,-YT,0,0],[0,0,0,0,0,0,0,T,-Z,0],[0,0,0,0,0,0,0,0,T,-Z]]
M=matrix(L)
M.lll()
but this gives an error message AttributeError: 'sage.matrix.matrix_integer_dense.Matrix_integer_dense' object has no attribute 'lll'