$=P The DLP prototype is implemented in a (syntactic) variant of POOL-X. The implementation language used deviates from POOL-X as described in  [Am88] in that lowercase keywords are used. Moreover we have replaced the keywords BEGIN, END and ROUTINE by respectively \{ , \} and fn. We also allow the use of a macro-processor for which definitions of the form [] df m(X) = ... are accepted. We have adapted the C-preprocessor for this purpose. For defining shorthands for types we use alias definitions that are like macro definitions, except that parameters are not allowed. A more detailed description of our implementation language is given in section \ref{impl/comp/proto:lang}. As syntactic sugar POOL-X also allows the form q[n], for objects q and n, to be used for the method call q!put1(n,v) when it occurs on the left hand side of an assignment q[n] := v and for the call q!get1(n) otherwise. The corresponding methods for q must be defined by the user. This notation may however also be used for arrays, in the usual way.