Past exam of the year 1 of the computer science course of the University of Oxford / 2018 / Digital systems, linear algebra, introduction to formal proof / 1 / c

With the encoding in part (b), $y=A$ is a valid Moore machine output equation. Among reachable states, $A=1$ exactly at $S_4$. This uses unused output-table entries as don't-care conditions. If one instead wants the output to be zero in every unused state, use $y=A\bar{B}\bar{C}$; that extra requirement does not change any output from a valid state.