I(A;B)<=I(A;B|C)+I(A;B|D)+I(C;D)
I(AE;B)<=I(AE;B|C)+I(AE;B|D)+I(C;D)
I(A;B)<=I(A;B|CE)+I(A;B|D)+I(CE;D)
I(AE;BE)<=I(AE;BE|CE)+I(AE;BE|DE)+I(CE;DE)