I'm trying to negate an $and clause with MongoDB and I'm getting a MongoError: invalid operator: $and message back. Basically what I want to achieve is the following:

query = { $not: { $and: [{institution_type:'A'}, {type:'C'}] } }

Is this possible to express in a mongo query?

Here is a sample collection:

{ "institution_type" : "A", "type" : "C" }
{ "institution_type" : "A", "type" : "D" }
{ "institution_type" : "B", "type" : "C" }
{ "institution_type" : "B", "type" : "D" }

What I want to get back is the following:

{ "institution_type" : "A", "type" : "D" }
{ "institution_type" : "B", "type" : "C" }
{ "institution_type" : "B", "type" : "D" }