private void ReadFunctions(CompoundExpression eFunctions, Domain d)
 {
     foreach (Expression eSub in eFunctions.SubExpressions)
     {
         if (eSub.ToString() != ":functions")
         {
             if (eSub is CompoundExpression)
             {
                 CompoundExpression eFunction = (CompoundExpression)eSub;
                 //BUGBUG - not validating function parameters
                 d.AddFunction(eFunction.Type);
             }
         }
     }
 }