For each question give two rules of a $\backslash$Sigma rewriting system $($for the $\backslash$Sigma given$)$

that generate the language shown from the initial word given. b$\}$

$3.$ I $=$ a; L $=\{$c$,$ cb$,$ cbb$,$ cbbb$,...\}$; $\backslash$Sigma $=\{$a$,$ b$,$ c$\}$