Modify event auth rules not to rely on depth
@@ -504,15 +504,15 @@ the state of the room.
state of the room. For example, a redacted ``join`` event will still
result in the user being considered joined.
-1. If type is ``m.room.create``, allow if and only if has depth 0 and it has no
+1. If type is ``m.room.create``, allow if and only if it has no
previous events - *i.e.* it is the first event in the room.
#. If type is ``m.room.member``:
a. If ``membership`` is ``join``:
- i. If the previous event in the room graph is an ``m.room.create``, the
- depth is 1 and the ``state_key`` is the creator, allow.
+ i. If the only previous event is an ``m.room.create``
+ and the ``state_key`` is the creator, allow.
#. If the ``sender`` does not match ``state_key``, reject.
