TJ wrote:

...

Use table-set! without the third argument (the "value" argument).

Thanks for pointing this out. I did miss this from checking the manual (and the sources), I was too fixed on expecting a separate procedure.

(Honestly I'm not sure that this approach is a good idea, for error tracking it's better if the procedures one uses take only the number of arguments they should for the purpose one wants. I can't see an advantage right now. But I can always wrap table-set! with my own table-set!/table-delete! definitions of course.)

Christian.