@Christian Wolinski can you explain what each line in your code does?

I am baffled by the syntaxis.

What is op? What is procname? What does it do to call a function followed by a Domain between brackets?

@tomleslie this is great, thank you!

@tomleslie thank you!

Unfortunately it does not seem to work in my Maple version.

When I open your attachment and execute the cells, I get this output:

Small nitpick: in the procedure you should be using ED instead of GI, since I want it to work with other domains.

@vv Attached you can find my worksheet.

My impression is that I am doing exactly as you, but for some reason it does not work.

I am really confused :P

EEA.mw

@vv I have tried your suggestion, using for example r_aux := ED[`-`](r_0, ED[`*`](q, r_1));

I get the following error:

Error, (in GI[`*`]) invalid subscript selector

@tomleslie I have now added self-contained code reproducing the mistake.

@tomleslie I am not using custom domains or the LinearAlgebra module, I am using the built-in Domains module, apologies for not making this clear.

I was also surprised that the symbol _i was used over I.