Checking types in MAGMA

Question

In using MAGMA, I always get type errors. How do you find out what the type of something is?

For example, I have made an empty set $e := []$, how would I make MAGMA print out the type of $e$?

Also, when using the MAGMA handbook, I see types in entries like

HKZ(X) : ModMatRngElt -> ModMatRngElt, AlgMatElt

but what are these types? I can't find any documentations for these types themselves, though I can guess what they are like, by inferring from in what functions they appear.

Answer 1

There are two comments that might help you here:

Parent(e);
Type(e);

The first returns the parent of $e$, where $e$ is contained in (e.g. vector space of 2x2 matrices over finite field of order two). This is useful as magma sometimes want to be have elements in the same universe before performing operations on them, you might need to cast it using $!$ or ChangeUniverse first.
The second one gives you the type, exactly as you want it, as AlgMatElt, etc.

To find more about it, just search "type" in the handbook and go to the first entry. :)