lpsinvelm: 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/lpsinvelm - from package: mcrl2

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

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