wam2ma: 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 CentOS possible default full paths are:

/usr/bin/wam2ma - from package: gprolog
/usr/lib64/gprolog-1.3.1/bin/wam2ma - from package: gprolog

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/lib/gprolog-iso/bin/wam2ma - from package: gprolog

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

Error in other languages:
wam2ma: bevel nie gevind nie
wam2ma: comandă negăsită
wam2ma: comando não encontrado
wam2ma: commande introuvable
wam2ma: command not found
wam2ma: käsku ei ole
wam2ma: không tìm thấy lệnh
wam2ma: komanda nerasta
wam2ma: Kommando nicht gefunden.
wam2ma: kommandot finns inte
wam2ma: komut yok
wam2ma: nie znaleziono polecenia
wam2ma: níor aimsíodh an t-ordú
wam2ma: no se encontró la orden
wam2ma: no s'ha trobat l'ordre
wam2ma: opdracht niet gevonden
wam2ma: parancs nem található
wam2ma: perintah tidak ditemukan
wam2ma: príkaz nenájdený
wam2ma: příkaz nenalezen
wam2ma: команда не найдена
wam2ma: командата не е открита
wam2ma: 命令找不到
wam2ma: コマンドが見つかりません