Add missing primitive implementation for the plain interpreter.
#LyX 1.3 created this file. For more info see http://www.lyx.org/
\lyxformat 221
\textclass article
\language english
\inputencoding auto
\fontscheme default
\graphics default
\paperfontsize default
\papersize Default
\paperpackage a4
\use_geometry 0
\use_amsmath 0
\use_natbib 0
\use_numerical_citations 0
\paperorientation portrait
\secnumdepth 3
\tocdepth 3
\paragraph_separation indent
\defskip medskip
\quotes_language english
\quotes_times 2
\papercolumns 1
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\layout Standard
\begin_inset Float figure
wide false
collapsed false
\layout Standard
\begin_inset Graphics
filename kernel-graph.ps
width 60page%
keepAspectRatio
\end_inset
\layout Caption
The ThiNG Kernel
\end_inset
\the_end