lambda: 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 CentOS possible default full paths are:

/usr/bin/lambda - from package: texlive

You may install the required package with command yum install {package}

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