\def\cprime{$'$}
\begin{thebibliography}{1}

\bibitem{ACU}
Thorsten Altenkirch, James Chapman, and Tarmo Uustalu.
\newblock Monads need not be endofunctors.
\newblock In {\em Foundations of software science and computational
  structures}, volume 6014 of {\em Lecture Notes in Comput. Sci.}, pages
  297--311. Springer, Berlin, 2010.

\bibitem{ACU2}
Thorsten Altenkirch, James Chapman, and Tarmo Uustalu.
\newblock Monads need not be endofunctors.
\newblock {\em Logical Methods in Computer Science}, 11(1:3):1--40, 2015.

\bibitem{FPT}
Marcelo Fiore, Gordon Plotkin, and Daniele Turi.
\newblock Abstract syntax and variable binding (extended abstract).
\newblock In {\em 14th {S}ymposium on {L}ogic in {C}omputer {S}cience
  ({T}rento, 1999)}, pages 193--202. IEEE Computer Soc., Los Alamitos, CA,
  1999.

\bibitem{Lawvere}
F.~William Lawvere.
\newblock Functorial semantics of algebraic theories and some algebraic
  problems in the context of functorial semantics of algebraic theories.
\newblock {\em Repr. Theory Appl. Categ.}, (5):1--121, 2004.
\newblock Reprinted from Proc. Nat. Acad. Sci. U.S.A. {{\bf{5}}0} (1963),
  869--872 [MR0158921] and {{\i}t Reports of the Midwest Category Seminar. II},
  41--61, Springer, Berlin, 1968 [MR0231882].

\bibitem{MacLane}
S.~MacLane.
\newblock {\em Categories for the working mathematician}, volume~5 of {\em
  Graduate texts in {M}athematics}.
\newblock Springer-Verlag, 1971.

\bibitem{LandC}
Vladimir Voevodsky.
\newblock Lawvere theories and c-systems.
\newblock {\em arXiv 1512.08104}, pages 1--15, 2015.

\end{thebibliography}