Robust coding of expired tasks

Thanks, that is good news indeed, because long chains of branching tasks coded with suicide triggers were becoming unmaintanable after a certain chain length.

But my question remains - what do I do with this construct I mentioned above.

I want the post-processing of the downloaded file and the merging of that processed file into the downloaded file to be omitted only if the download expired (the server only keeps files online for 7 days , so it’s pointless attempting the download after that, hence the expiration)

In this discussion Workflow with suicide triggers I saw the construct

@clock => a? => b? => c?
a:finish => housekeeping

So can I translate my above construct into cylc8 like this?

    download => run_processing? => merge_files? => housekeep?

or like this?

    download? => run_processing? => merge_files? => housekeep

where do the question marks go?

Thanks!