[0,1] true if A is centered(i.e. intersection of all planes not empty)
Note:
The algorithm uses the rank of matrix: Ax=b has a solution iff
rank(A) = rank(A|b)
Example:
LIB "arr.lib";
ring R = 0,(x,y,z),dp;
arr A= ideal(x,y,x-y+1); // centerless
arrCentral(A);
==> 0
arr B= ideal(x,y,z); // central with center being the origin
arrCentral(B);
==> 1
arr C= ideal(x+1,2y+1,-z+1); // central with center (-1,-1/2, 1)
arrCentral(C);
==> 0