Simplify the given logic functions through a direct use of Boolean algebra:

i$.$ y$1=($s$1$ bar$\backslash$geocircle s$3)$ XOR $($s$4$ bar$)$

ii$.$ y$2=($b$1$ bar b$3+$ b$2(($b$1+$ ba$)$bar$)))$ bar

iii. y$3=($z $+($w$($u$\text{'}+$ xz$)\text{'})+$ wx$)\text{'}$