Re: sqrt(-1) and %i

> I guess the Expression domain is rather poorly named...

That is also what I think. If I think of expression I rather mean 
something like a Mathematica or Maple expression. This is more like 
SExpression in Axiom. The current Axiom-Expression domain certainly 
works fine for a lot of cases, but it is misleading to call it 
expression. Actually, if you think of it, would you agree that 
Expression must have a parameter? If one knows the internals, that is 
clear, but it is not the usual understanding of "expression".

Just my two cents... Oh, one cent.

Ralf

PS: Look at HyperDoc for Expression. As description it says:

   Expressions involving symbolic functions.

For me that is no description at all.