pval: 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/pval - from package: snacc

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

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