Controlling vertical space within a “tabbing” environment

Question

I'm using the "tabbing" environment to typeset algorithms. Because I'm using math formulas within the algorithms (yes I know about specific packages to do this), the vertical space needs a bit of (manual, case by case) tweaking, yet I have been unable to affect the vertical spacing of individual lines.

Any reference to vertical spacing and "tabbing" I could find were about how to suppress the spacing at the beginning and end of the environment---which is not my concern.

Below is some (I believe) minimal code snippet to reproduce the problem. On my system, this renders as a list of "test" lines, with the spacing always the same everywhere.

\documentclass{article}

\begin{document}

\begin{tabbing}
  \=X \= X \= XXX\= XXX \= XXX\=\kill
  \>\>test\\
  \>\>test\\
  \>\>test\\\vspace{10cm}
  \>\>test\\
  \>\>test\vspace{10cm}\\
  \>\>test\\
  \>\>test\bigskip\\
  \>\>test\\\bigskip
  \>\>test
\end{tabbing}

\end{document}

Answer 1

You can use the optional argument for \\:

\documentclass{article}

\begin{document}

\begin{tabbing}
  \=X \= X \= XXX\= XXX \= XXX\=\kill
  \>\>test\\
  \>\>test\\
  \>\>test\\[1cm]
  \>\>test\\
  \>\>test\\
  \>\>test\\[2ex]
  \>\>test\\
  \>\>test\\
  \>\>test
\end{tabbing}

\end{document}