How to pull an array element (which is a document) in mongodb?

Assume the assembly is as follows:

db.mytests.find()
{ "_id" : ObjectId("4fb277b89b8295a790efde44"), 
"mylist": [ 
    { "foo1" :"bar1", "foo2" : "bar2" }, 
    {"foo1" : "bar3", "foo2" : "bar4" } 
], 
"nonlist" : "nonlistVal" }

I want to delete the document in mylistwhose foo1equal bar1, after reading the mongodb update file . this:

db.mytests.update({},{$pull:{'mylist':{'mylist.$.foo1':'bar1'}}})

but it failed. To find out the problem, I insert a new array into mytestsusing this:

db.mytests.update({},{$set:{'anotherList':[1,2,3,4]}})

and then using db.mytests.update({},{$pull:{'anotherList':{$gt:3}}})to pull an element 4in an array anotherList, it succeeds.

I assumed that the problem is with mylist.$.foo1? Can you tell me the correct way to delete a document element in an array?