Reduce space between makebox and enumerate

Question

This question is closely related to Command for switching exercise styles.

In the following problem the following code was deviced

\newcommand{\Problem}{
    \refstepcounter{problem}
    \vspace{3.25ex plus 1ex minus .2ex}\par
    \noindent\makebox[0pt][r]{\protect\fbox{\UNIproblemnumber}\qquad}%
    \par\vskip-\baselineskip\vskip-\parskip
}

Which removes the vertical spacing after the makebox command. Something like

\Problem

\lipsum[75]

Produces

Which is great. The problem arises when an enumerate environment directly follows

A way to remedy this is to insert \vspace{-\topsep} manually between \Problem and the enumerate environment. However, using this globally messes us the spacing between \Problem and normal paragraphs.

• Question: Is there a way to reduce the spacing between \Problem and enumerate without effecting the spacing between \Problem and normal paragraphs?

Code

\documentclass{article}
\usepackage{lipsum}
\usepackage{enumitem}
\usepackage{xcolor}

\newcounter{problem}
\newcommand{\UNIproblemnumberformat}{\bfseries\color{blue}}
\newcommand{\UNIproblemnumber}{\UNIproblemnumberformat\arabic{problem}}

\newcommand{\Problem}{
    \refstepcounter{problem}
    \vspace{3.25ex plus 1ex minus .2ex}\par
    \noindent\makebox[0pt][r]{\protect\fbox{\UNIproblemnumber}\qquad}%
    \par\vskip-\baselineskip\vskip-\parskip
}

\setlength\parindent{0pt}

\begin{document}

\Problem 

\begin{enumerate}
    \item 
\end{enumerate}

\Problem

\lipsum[75]

\begin{enumerate}
    \item Hi
\end{enumerate}

\lipsum[66]

\end{document}

Answer 1

This is best solved with an environment:

\documentclass{article}
\usepackage{enumitem}
\usepackage{xcolor}

\usepackage{lipsum}

\newcommand{\UNIproblemnumberformat}{\bfseries\color{blue}}

\newlist{Problemenv}{enumerate}{1}
\setlist[Problemenv]{
  labelwidth=3em,
  align=left,
  label=\fbox{\UNIproblemnumberformat\arabic*},
  resume
}
\newenvironment{Problem}{\Problemenv\item}{\endProblemenv}
\newenvironment{penumerate}{\enumerate[leftmargin=*]}{\endenumerate}

\begin{document}

\begin{Problem}
\begin{penumerate}
    \item \lipsum[3][1-2]
    \item \lipsum[3][3-5]
\end{penumerate}
\end{Problem}

\begin{Problem}
\lipsum[75]

\begin{enumerate}
    \item Hi
\end{enumerate}

\lipsum[66]
\end{Problem}

\end{document}

If you want the toggle for the format, here is how.

\documentclass{article}
\usepackage{enumitem}
\usepackage{xcolor}
\usepackage{etoolbox}
\usepackage{changepage}

\usepackage{lipsum}

\newtoggle{inline}
\settoggle{inline}{true}
\newcommand{\UNIproblemnumberformat}{\bfseries\color{blue}}

\newlist{Problemenv}{enumerate}{1}
\setlist[Problemenv]{
  labelwidth=\dimexpr3em\relax,
  align=left,
  label=\fbox{\UNIproblemnumberformat\arabic*},
  resume
}
\newenvironment{Problem}
 {%
  \setlength{\parindent}{0pt}%
  \iftoggle{inline}
   {\Problemenv\item}
   {%
    \adjustwidth{\dimexpr3em-\labelsep\relax}{0pt}%
    \refstepcounter{Problemenvi}\subsection*{Problem \theProblemenvi}%
   }%
 }
 {\iftoggle{inline}{\endProblemenv}{\endadjustwidth}}
\newenvironment{penumerate}{\enumerate[leftmargin=*]}{\endenumerate}

\begin{document}

\begin{Problem}
\begin{penumerate}
    \item \lipsum[3][1-2]
    \item \lipsum[3][3-5]
\end{penumerate}
\end{Problem}

\begin{Problem}
\lipsum[75]

\begin{enumerate}
    \item Hi
\end{enumerate}

\lipsum[66]
\end{Problem}

\togglefalse{inline}

\begin{Problem}
\begin{penumerate}
    \item \lipsum[3][1-2]
    \item \lipsum[3][3-5]
\end{penumerate}
\end{Problem}

\begin{Problem}
\lipsum[75]

\begin{enumerate}
    \item Hi
\end{enumerate}

\lipsum[66]
\end{Problem}

\end{document}

Answer 2

I would do the following. Since you're already using enumitem you can create a new list as follows:

\newlist{myenumerate}{enumerate}{1}
\setlist[myenumerate,1]{label=\arabic*., topsep=0pt}

The key, topsep=0pt, is what eliminates the undersired space.

So whenever you need enumerated lists after a problem, just call it thus:

\begin{myenumerate}
  \item
\end{myenumerate}

The whole code is:

\documentclass{article}
\usepackage{lipsum}
\usepackage{enumitem}
\usepackage{xcolor}

\newcounter{problem}
\newcommand{\UNIproblemnumberformat}{\bfseries\color{blue}}
\newcommand{\UNIproblemnumber}{\UNIproblemnumberformat\arabic{problem}}

\newcommand{\Problem}{
    \refstepcounter{problem}
    \vspace{3.25ex plus 1ex minus .2ex}\par
    \noindent\makebox[0pt][r]{\protect\fbox{\UNIproblemnumber}\qquad}%
    \par\vskip-\baselineskip\vskip-\parskip
}

\newlist{myenumerate}{enumerate}{1}
\setlist[myenumerate,1]{label=\arabic*., topsep=0pt}

\setlength\parindent{0pt}

\begin{document}

\Problem

\begin{myenumerate}
    \item \lipsum[75]
\end{myenumerate}

\Problem

\lipsum[75]

\begin{myenumerate}
    \item Hi
\end{myenumerate}

\lipsum[66]

\end{document}

which produces:

You can also tweak the space left to the number by setting the keys leftmargin and itemindent.