gaphor: 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/gaphor - from package: gaphor

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

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