intercalc: 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/bin/intercalc - from package: clc-intercal

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