prelude-lml: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/prelude-lml - from package: prelude-lml

You may install the required package with command apt-get install {package}
Error in other languages:
prelude-lml: bevel nie gevind nie
prelude-lml: comandă negăsită
prelude-lml: comando não encontrado
prelude-lml: commande introuvable
prelude-lml: command not found
prelude-lml: käsku ei ole
prelude-lml: không tìm thấy lệnh
prelude-lml: komanda nerasta
prelude-lml: Kommando nicht gefunden.
prelude-lml: kommandot finns inte
prelude-lml: komut yok
prelude-lml: nie znaleziono polecenia
prelude-lml: níor aimsíodh an t-ordú
prelude-lml: no se encontró la orden
prelude-lml: no s'ha trobat l'ordre
prelude-lml: opdracht niet gevonden
prelude-lml: parancs nem található
prelude-lml: perintah tidak ditemukan
prelude-lml: príkaz nenájdený
prelude-lml: příkaz nenalezen
prelude-lml: команда не найдена
prelude-lml: командата не е открита
prelude-lml: 命令找不到
prelude-lml: コマンドが見つかりません