They can be divided into three classes :
The classification of Moufang 4 - gons was the hardest of all , and when Tits and Weiss started to write it up , a hitherto unnoticed type came into being , arising from groups of type F4 .
Moufang 4 - gons can be divided into three classes :
The classification of Moufang 4 - gons was the hardest of all , and when Tits and Weiss started to write it up , a hitherto unnoticed type came into being , arising from groups of type F4 .