pmxab: 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/pmxab - from package: pmx

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

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