Is it possible to write subscript?

[ag91]

Hello,

Thanks to maintain this piece of software, it is really an useful tool!
I was wandering if it allows to write subscript: I tried something LaTex-ish like k_1, but that does not work.
Is this supported?

[stathissideris]

Unfortunately this is not supported.

[ju-sh]

Unicode subscript characters (or at least what look them) could help. Like k₁.