F$($x$,$y$,$z$)=$ x$\text{'}$yz $+$ x$\text{'}$yz$\text{'}+$ x$\text{'}$y$\text{'}$z $+$ xyz $+$ xy$\text{'}$z $+$ xy$\text{'}$z$\text{'}+$ xyz$\text{'}$

In this case, the sum of the products is the sum of what?