slt: 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/slt - from package: slt

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