variable names with sub-indices



Hi

Could someone please tell me what
is the most correct way to use 
variable names with sub-indeces in Maxima.

If I want to have a large (non-fixed)
number of indeterminates:
x_1, x_2, ... x_n

should I use
x[1], x[2], ..., x[n] (where x should no have 
been assigned any value)?
should I use instead 
"x"[1], ...
or concat("x",1),...  or
concat(x,1) (x should have been assigned
no value)?

  Fabrizio