GenericBasicExpression result = null;
if (namespace.equals (NamespaceCache.SLIDE_URI)
&& name.equals (Literals.ISPRINCIPAL))
result = new IsPrincipalExpression (e, getRequestedResourcePool());
else if (namespace.equals (NamespaceCache.SLIDE_URI)
&& name.equals (Literals.NOT_ISPRINCIPAL))
result = new NotIsPrincipalExpression (e, getRequestedResourcePool());