gabplr's profile - activity

In Sage 6.3 (both command line and notebook), I tried to define a vector over Q[X] as follows

R = PolynomialRing(QQ,'x')
X = polygen(R)
a, b = X^4-1, X-1
vec =  vector(R,[a, b])

This produces an error

TypeError: not a constant polynomial

By contrast, the following works:

sage: vec =  vector(R,[[a],[b]])
sage: vec
(x^4 - 1, x - 1)

Is this a bug or could someone explain me why?