Thankyou very much Karsten.

My understanding of how the various nodes work is very poor. Some study should help, (after Work:-).
I'm wondering if the logic Compare node would help, and about its inputs and outputs.
Could the Compare node substitute for the nonexistant Selector node?
Concatenate sounds useful, to combine the 3(+) Math nodes, but somehow the 3 speeds need to be switched between.

Didn't someone start a Wiki on Nodes?

- Brian