YEY, i feel relieved :) and what do you mean with "all you probably needed to do was say what T does to the basis vectors in β1"? is a=x, b=x, c=y, d=z \ \forall \ (x,y,z)∈V \ and \ (a,b,c,d)∈U wrong? as you can see, i have more problems finding out what i need to do, rather than doing it
I...