\begingroup

\newcommand{\reals}{\mathbb{R}}

\input{Envelope_2_ref/intro}
\input{Envelope_2_ref/lower_envelope_2}
\input{Envelope_2_ref/upper_envelope_2}
\input{Envelope_2_ref/lower_envelope_x_monotone_2}
\input{Envelope_2_ref/upper_envelope_x_monotone_2}
%\input{Envelope_2_ref/EnvelopeDiagram}
%\input{Envelope_2_ref/Env_default_diagram}
\endgroup