Mistake in Wikipedia CSG example?
If I am not mistaken, a simpler CS grammar is possible.  Here it is:


$S \rightarrow ABSc$
$S \rightarrow Abc$
$BA \rightarrow XA$
$XA \rightarrow XY$
$XY \rightarrow AY$
$AY \rightarrow AB$
$A \rightarrow a$
$Bb \rightarrow bb$.


A derivation for the string $aaabbbccc$ is

$\Rightarrow_1 ABSc\\\Rightarrow_1 AB\textbf{ABSc}c\\\Rightarrow_2 ABAB\textbf{Abc}cc\\\Rightarrow_3 A\textbf{XA}BAbccc\\\Rightarrow_4 A\textbf{XY}BAbccc\\\Rightarrow_5 A\textbf{AY}BAbccc\\\Rightarrow_6 A\textbf{AB}BAbccc\\\dots\\\Rightarrow_{3-6}AAB\textbf{AB}bccc\\\Rightarrow_{3-6}AA\textbf{AB}Bbccc\\\Rightarrow_{7...}\textbf{aaa}BBbccc\\\Rightarrow_8 aaaB\textbf{bb}ccc\\\Rightarrow_8 aaa\textbf{bb}bccc$