Hi, as I'm debugging and trying to adapt the mentioned function package for permanent-transitory decompositions I will probably be sending a couple of emails with bug reports. (Also in spirit with the call for reporting function packaging bugs at the conference.) Ok, so here we go: I have the following (example) function which specifies a "null" default for an optional list argument: function scalar defaultnullcheck(const list mylist[null]) print "nothing happening" end function If I package that function and call it in the GUI I don't get the "null" default inserted in the place for the mylist argument. Instead another list (probably the first that was created in the session) is inserted there. I propose to insert the "null" keyword instead. cheers, sven