append a variable to a vector
I would like to define a new vector in Sage $\vec{u} = [O, P, \sigma]$ using a previously defined vecotor $\vec{x} = [O, P]$ and a new variable $\sigma$.
My code looks like:
var(O, P');
var('sigma');
x = vector([O,P]);
u = vector([x, sigma]);
Which gives an error:
TypeError: unable to find a common ring for all elements
Apparently this is because vector() requires the variables to be of the same ring. In my case
x.parent()
Vector space of dimension 2 over Symbolic Ring
and
sigma.parent() Symbolic Ring
There is any way how to connect this two objects ($\vec{x}$, $\sigma$) together to create one vector?