\Head{}
\L{\LB{    btree \= \^node{\PC}}}
\L{\LB{\Proc{}    node  \= \K{record}}}
\L{\LB{        d {\DP} $0$..$2$\*M{\PC}}}
\L{\LB{        k {\DP} \K{array} \[$1$..$2$\*M\] \K{of} typekey{\PC}}}
\L{\LB{        p {\DP} \K{array} \[$0$..$2$\*M\] \K{of} btree}}
\L{\LB{        \K{end}{\PC}}}
