lpsrewr: 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/lpsrewr - from package: mcrl2

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

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