fndelt: command not found

Have You tried accessing the binary with the full path?

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/lib/x86_64-linux-gnu/gap/pkg/guava/bin/leon/fndelt - from package: gap-guava-bin

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