W state as a product structure

This note investigates the SVD of the W-sate as used in lecture II.  Sheet 0 of the HWK does something similar.  
http://www.comlab.ox.ac.uk/activities/quantum/course/

w=(({{0, 1, 1, 0}, {1, 0, 0, 0}}))

{s,v,d}=SingularValueDecomposition[w]

MatrixForm[d]

MatrixForm[s]

MatrixForm[v]