trisetcmp: 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/trisetcmp - from package: regina-normal

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

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