Verification of comprehension the core idea of P27 Solution via Mapping Method ( second one proposed in ege23.doc )

Consider following system in Boolean variables

(x1 v x2) ^ (x1^x2 =>x3) ^ ((x1 =>y1) =>z1)=1
(x2 v x3) ^ (x2^x3 =>x4) ^ ((x2 =>y2) =>z2)=1
(x3 v x4) ^ (x3^x4 =>x5) ^ ((x3 =>y3) =>z3)=1
(x4 v x5) ^ (x4 =>y4) ^ ((x5 =>y5) =>z5) =1

First we build diagram between x1x2 and x2x3 keeping track of all bits pairs y1z1 in more complicated situation then in P27 ( four combinations to consider {00,01,10,11} )
Keeping in mind matching x2 bit on the left and right hand sides
Second  we build diagram between x4x5 and y4y5  keeping track of all bits pairs of z5 {0,1}