@Carl Love It works now! Thanks for your assistance and patience!

@Carl Love Wow, you have really strong feelings about 2D. Keep in mind that some of don't have the experience you do with scientific software and this interface helps those who aren't so savvy. 

• My cursor is to the left of a prompt. My cursor is blinking. The prompt is a reddish/maroonish color.
• The pull-down says 2D Input

Attached is an image that might help.

command-j.pdf

@Carl Love I tried what you suggested and I'm still getting the same error. Can't figure out what I'm doing wrong. Sorry to be a bother.

@Carl Love Okay. I've always used 2D input. What is the 'best' way to convert it to 1D input?

@Carl Love So, I tried to use both and they are both giving me an error. I can't figure out why. I've attached the worksheets. TreeToPrüfer.mw Download PrüferToTree.mw

@Carl Love I have never used heap before. You've motivated me to learn more about it. I particularly like your statistical analysis of the TreeToPrufer code. It is rather efficient. Much appreciated!

@Carl Love I'll use lprint.

@Carl Love  I've used that approach before. I find it strange that solve ignores assumptions.

@Carl Love I completely missed your response. This does what I need. Thanks!

@acer This ended up being much simpler than I was making it. Thanks! I'll have a look the the ArrayTool:-BlockCopy command.

@dharr This is perfect! Thank you!

@Carl Love As always, when I get an answer to a question here, I often learn a lot more than I expected to. Thanks much!

@acer Sorry about the ambiguity, I was thinking the former. Would it matter, though?

@acer Supposing we have a universal set of all reals, could this method be adapted to work with complements? For example, how could I do the intersection of the complement of A and B?

@acer Thanks so much. Just what I needed!