epsilon: command not found

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/epsilon - from package: epsilon-bin

You may install the required package with command apt-get install {package}

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