Zermelo's Well-Ordering Theorem in Type Theory
نویسنده
چکیده
Taking a `set' to be a type together with an equivalence relation and adding an extensional choice axiom to the logical framework (a restricted version of constructive type theory) it is shown that any `set' can be well-ordered. Zermelo's rst proof from 1904 is followed, with a simpli cation to avoid using comparability of well-orderings. The proof has been formalised in the system AgdaLight.
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