mcrl22lps: 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/mcrl22lps - from package: mcrl2

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

Error in other languages:
mcrl22lps: bevel nie gevind nie
mcrl22lps: comandă negăsită
mcrl22lps: comando não encontrado
mcrl22lps: commande introuvable
mcrl22lps: command not found
mcrl22lps: käsku ei ole
mcrl22lps: không tìm thấy lệnh
mcrl22lps: komanda nerasta
mcrl22lps: Kommando nicht gefunden.
mcrl22lps: kommandot finns inte
mcrl22lps: komut yok
mcrl22lps: nie znaleziono polecenia
mcrl22lps: níor aimsíodh an t-ordú
mcrl22lps: no se encontró la orden
mcrl22lps: no s'ha trobat l'ordre
mcrl22lps: opdracht niet gevonden
mcrl22lps: parancs nem található
mcrl22lps: perintah tidak ditemukan
mcrl22lps: príkaz nenájdený
mcrl22lps: příkaz nenalezen
mcrl22lps: команда не найдена
mcrl22lps: командата не е открита
mcrl22lps: 命令找不到
mcrl22lps: コマンドが見つかりません