COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	\input basic
C00004 ENDMK
C⊗;
\input basic
\def \BR #1:#2.{\vskip 2pt\hjust{\hjust to 16pt{#1$\mapsto$\hfill}#2}}
\def \BS #1:#2.{\hjust{\hjust to 16pt{#1$\mapsto$\hfill}#2}}
\def \TR #1,#2{\hjust{$\left[\vcenter{\vjust{\hjust{#1}#2}}\right.$}}
\def \ST #1{\hjust{\it subtree #1}}
\save9 \hjust{first subtree}
\save8 \TR  WK@P3,{\BR t:SAFE .\BR f:LOST .}
\save8 \TR  K@P2 ,{\BR t:\box8.\BR f:LOST .}
\save7 \TR  WK@P3,{\BR t:SAFE .\BR f:LOST .}
\save7 \TR  R>>N ,{\BR t:\box7.\BR f:LOST .}
\save8 \TR  N-WK ,{\BR 1:\box8.\BR 2:<>.\BR 3:\box7.}
\save8 \TR  R-WK ,{\BR 1:\box8.\BR 2:SAFE .\BR 3:SAFE .}
\save7 \hjust{second subtree}
\save6 \TR  WK|R|,{\BR t:SAFE .\BR f:LOST .}
\save6 \TR  WK@P3,{\BR t:\box6.\BR f:LOST .}
\save6 \TR  K@P2 ,{\BR t:\box6.\BR f:LOST .}
\save6 \TR  R>>N ,{\BR t:\box6.\BR f:LOST .}
\save6 \TR  N-WK ,{\BR 1:LOST .\BR 2:LOST .\BR 3:\box6.}
\save6 \TR  K-WK ,{\BR 2:\box6.\BR 3:LOST .}
\save6 \TR  K-N  ,{\BR 1:LOST .\BR 2:LOST .\BR 3:\box6.}
\save8 \TR  K-R  ,{\BR 1:\box8.\BR 2:\box7.\BR 3:\box6.}
\save9 \TR  APPR ,{\BR t:\box9.\BR f:\box8.}
\box9
\vfill\end