Linz Section $6\mathrm{.}2$ exercises $4,5,12$

$4.$ Transform the grammar with productions

$S$baAB,

$A$bAB$\frac{|}{},|$

$B$BAa$|A\frac{|}{}$

into Chomsky normal form.

$5.$ Convert the grammar

$SAB|aB|$

$A$abb$\frac{|}{}|$

$B$bbA

into Chomsky normal form.

$12.$ Convert the grammar

$Sab|aS|aaS|aSS|$

into Greibach normal form.