Documentation

Marginis.CoquandSchuster2011

Unique paths as formal points #

by Thierry Coquand, Peter Schuster

The paper mentions Weak König's Lemma.

We (define and) prove:

For Fin 1 the path is indeed (obviously) unique.

def tree {α : Type} (T : Set (List α)) :
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    def has_a_path {α : Type} (T : Set (List α)) :
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      def WKL {α : Type} :
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        theorem wklFin0 :
        WKL
        theorem zerolist (σ : List (Fin 1)) :
        σ = List.replicate σ.length 0
        theorem wklFin1 :
        WKL