Ulrich Thiel

Well, I tried that with the office today, but you know...the drill...

Oh yeah, they turned off the radio after my request but then started the drill instead.

Why does A need to be an automorphism? It defines a map V -> V (V has a fixed basis). In Magma ``` > V:=VectorSpace(Rationals(),3); > A:=Matrix(Rationals(),3,3,[0,1,-1, 1,0,-1, 0,0,-1]); >...

> Since `VectorSpace(F, n)` always produces a free modulo of rank `n`, we have a fixed basis and there is no ambiguity. > > We can just make it work...

So, I'm supposed to do ``` f = ModuleHomomorphism(V, V, A) f(v) ``` Okay, makes sense in a way. But I feel that many users will fall into this trap;...

Sorry to interrupt but since we're at it: how do I get back the matrix of a vector space homomorphism as above? matrix(f) doesn't work. Also, inv(f) doesn't work. Do...