Skip to main content\( \newcommand{\identity}{\mathrm{id}}
\newcommand{\notdivide}{{\not{\mid}}}
\newcommand{\notsubset}{\not\subset}
\newcommand{\lcm}{\operatorname{lcm}}
\newcommand{\gf}{\operatorname{GF}}
\newcommand{\inn}{\operatorname{Inn}}
\newcommand{\aut}{\operatorname{Aut}}
\newcommand{\Hom}{\operatorname{Hom}}
\newcommand{\cis}{\operatorname{cis}}
\newcommand{\chr}{\operatorname{char}}
\newcommand{\Null}{\operatorname{Null}}
\def\Z{\mathbb Z}
\def\R{\mathbb R}
\def\Q{\mathbb Q}
\def\N{{\mathbb N}}
\def\C{\mathbb C}
\def\ba{{\mathbf{a}}}
\def\bb{\mathbf{b}}
\def\bh{{\mathbf{h}}}
\def\bu{{\mathbf{u}}}
\def\bv{{\mathbf{v}}}
\def\bw{{\mathbf{w}}}
\def\bx{{\mathbf{x}}}
\def\by{\mathbf{y}}
\def\bone{{\mathbf{1}}}
\def\bzero{\mathbf{0}}
\def\var{{\mbox{var}}}
\def\P{{\mathbb{P}}}
\def\E{{\mathbb{E}}}
\def\cA{{\mathcal{A}}}
\def\cB{{\mathcal{B}}}
\def\cC{{\mathcal{C}}}
\def\cP{\mathcal P}
\def\cE{\mathcal E}
\def\cO{\mathcal O}
\def\kin{k^{\mathrm{in}}}
\def\kout{k^{\mathrm{out}}}
\newcommand{\indeg}[1]{k^{\mathrm{in}}_{#1}}
\newcommand{\outdeg}[1]{k^{\mathrm{out}}_{#1}}
\tikzset{->-/.style={decoration={
markings,
mark=at position .5 with {\arrow{latex}}},postaction={decorate}}}
\newcommand{\lt}{<}
\newcommand{\gt}{>}
\newcommand{\amp}{&}
\)
Part II Generating Functions