Given four random variables, X1, X2, X3, and W,
It is known that X1 and X3 are conditionally independent given X2, i.e., I(X1;X3|X2)=0, where I represents the mutual information.
I want to prove
I(W;X3|X2)=I(W;X3|X1,X2)
Thanks in advanced !
Robert