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roger123
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What determines a model structure?

It is easy to prove that a model structure is determined by the following classes of maps (determined = two model structures with the mentioned classes in common are equal).

  • cofibrations and weak equivalences
  • fibrations and weak equivalences

The second statement follows immediately from the first by duality.

What about the following classes of maps/objects (A short argument would be very helpful)?

  1. cofibrations and fibrations
  2. cofibrant objects and weak equivalences
  3. cofibrant objects and fibrations
  4. cofibrant objects and fibrant objects

I think each of these classes determine the structure respectively. For the last one I suppose that one has to use framings but I cannot see how to do it.

roger123
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