% Task environment

\newcommand\taskname{Requisite}

\newcounter{taskc}
\setcounter{taskc}{0}
\renewcommand\thetaskc{\Roman{taskc}}

\newcounter{subtaskc}[taskc]
\setcounter{subtaskc}{0}
\renewcommand\thesubtaskc{%
  \thetaskc\thesubtaskc@part
}
\def\thesubtaskc@part{%
  \expandafter\ifnum\value{subtaskc}>0
    -\alph{subtaskc}%
  \fi
}

\newlength\taskspace

\newenvironment{task}[1][]%
  {%
    \setlength\taskspace{2ex}%
    \refstepcounter{taskc}%
    \begin{@task}[#1]%
  }%
  {\end{@task}\ignorespaces}


\newenvironment{subtask}[1][]%
  {%
    \list{}{%
      \leftmargin4ex
      \item\relax
    }%
    \setlength\taskspace{6ex}%
    \refstepcounter{subtaskc}%
    \begin{@task}[#1]%
  }%
  {%
    \end{@task}%
    \endlist
    \ignorespaces
  }



\newlength\@@subtaskcl
\newenvironment{@task}[1][]%
  {%
    \def\@@h{#1}%
    \goodbreak\leavevmode\@margin@sig
    \llap{%
      \raisebox{-\baselineskip}[0em][0em]{%
        \shortstack{%
          {\sc\taskname}\space\thesubtaskc
          \\
          \vphantom{M}%
          \ifx\@@h\empty\else
            {\small\@task@h#1||\,h}%
          \fi%
        }%
        \hspace{\the\taskspace}%
        % adjust width of the subtask text so that the task number lines up
        \settowidth\@@subtaskcl{\thesubtaskc@part}%
        \hspace{-\the\@@subtaskcl}%
      }%
    }%
    \ignorespaces
  }%
  {\goodbreak\ignorespaces}


\def\@task@h#1-#2||{#1--#2}