In the first provenance challenge, the processors ‘reslice’ and ‘softmean’ were designed with two roles:

1)	the function
2)	holds the results

Thus, they are both generators of data and retainers for the data. 
As ad consequence of splitting the challenge workflow into 3 parts: 

Part 1 executes ‘reslice’; 
Part 2 uses ‘reslice’ to recover the results of part 1 and executes ‘softmean’; 
Part 3 uses ‘softmean’ to recover the result of its previous execution for use in this final workflow. 

This was a quick fix for convenience.