Quotient topology

[jarctan]

• [ ] Definition of the opens of a quotient topology (as the preimage of opens)
• [ ] These opens form a topology
• [ ] Definition of an open map
• [ ] Definition of a quotient map (when the topology of the codomain is the quotient topology)
• [ ] A surjective, continuous, open map is a quotient map
• [ ] Composition of quotients is a quotient