Kmaps

4. It's time to build up the expression using the groups of $1$ that we got.
   
   Each one of the groups you created will correspond to one term/product in the sum-of-products formula that we built up. For example, if you created 3 groups in a certain Kmap, blue, red, and green, then the sum-of-products formula will look like:
   $E = $blue$ + $red$ + $green.
   
   Back to our example, we notice that the blue group corresponds to the case when $B$ is true (= $1$) and $A$ is false (= $0$) [and $C$ is both $0$ and $1$, so we disregard $C$ in this term], and that the red group corresponds to the case when both $B$ and $C$ are $1$s [and $A$ is both $0$ and $1$, so we disregard $A$ in this one term].
   
   Hence, our expression becomes $A'B$$ + $$BC$, which, when converted to the $x$, $y$, and $z$ variables, is $x'y$$ + $$yz$, which is the exact one simplified expression that we listed at the middle of slide 45!