how do I use upper indicies in Maxima?

Hello, all,

in TexMacs when I do
alpha[0];
I see small greek letter alpha with lower index zero.

1. How do I specify *upper* indicies?

2. Yet, how do I specify several indicies at once? "alpha[ij]; " isn't
what I want, because it refers to ij, but specifying coma looks
confusing (IMHO)

3. why I need to use %gamma to use small greek gamma, but small greek
alpha designated as "aplha". Could this inconsistency factored out
somehow? (by undefining another gamma definition?)

Thanks in advance,
Vadim.