`<1,2,3>`

, but can be problematic when the answer is a vector formula. In that case, this only works if the student answers an explicit vector, like `<x,y,x+y>`

, but will fail if the student enters `3<x,y,x+y>`

or `<1,0,0>.<x,y,x+y>`

. So I recommend using the dot product unless you are using one of the restricted vector contexts that prevents vector formulas.
You can also do

Vector(2,3,5)->extract(1)rather than

(Vector(2,3,5)->value)[0]to get just the first coordinate.

Note also that there is a `Complex-Vector`

context, so no need to set that up yourself. Just use

Context("Complex-Vector");There are also

`Complex-Point`

and `Complex-Matrix`

contexts.