$(\lambda x.xxx)(\lambda x.xxx)\to_\beta(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)\to_\beta(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)\to_\beta(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)\to_\beta(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)\to_\beta(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)(\lambda x.xxx)\to_\beta\dots$