[xiān lì]

set a precedent; create a precedent
開先例

have a precedent to go by
有先例可援

create a precedent for ...
為...創一先例

historic precedent
歷史先例

There is no lack of precedents in this connection.
不乏先例。

If he is allowed to do this, it will be a precedent for others.
如果允許他這樣做， 就會為別人開先例。