Checking whether points in space are cospherical

The is_cospherical command determines whether or not points are cospherical, i.e. whether they all lie on the same sphere.

is_cospherical takes L, a list or sequence of points.
is_cospherical(L) returns 1 if the points in L all lie on the same sphere, and 0 otherwise.

is_cospherical([2,0,0],[0,2,0],[sqrt(2),sqrt(2),0], [0,0,2],[2/sqrt(3),2/sqrt(3),2/sqrt(3)])

is_cospherical([2,0,0],[0,2,0],[1,1,0],[0,0,2],[1,1,1])