Description
Indexed variables provide the possibility of producing polynomial rings
R[x_0, x_1, ..., x_(n1)] in n variables, where n is not known in advance. If
x is an symbol, and i is an integer, then
x_i produces an indexed variable. After this has been done, an assignment
x_i=v will assign another value to it. A new sequence of indexed variables of length n assigned to the symbol
x can be produced with
x_1 .. x_n and that sequence can be used in constructing a polynomial ring.
i1 : ZZ/101[t_0 .. t_4]
ZZ
o1 = [t ..t ]
101 0 4
o1 : PolynomialRing

i2 : (t_0  2*t_1)^3
3 2 2 3
o2 = t  6t t + 12t t  8t
0 0 1 0 1 1
ZZ
o2 : [t ..t ]
101 0 4

Warning: the values of the indexed variables
t_i are stored in a global location, behind the scenes, so may not get garbage collected, even if
t is a local variable.