swipl-ld: 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/swipl-ld - from package: swi-prolog-nox
/usr/lib/swi-prolog/bin/amd64/swipl-ld - from package: swi-prolog-nox

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

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