Comments on: Agda Exercise: Proving that Mergesort Returns Ordered Lists http://www.iis.sinica.edu.tw/~scm/2007/agda-exercise-proving-that-mergesort-returns-ordered-list/ Research Blog of 穆信成 Shin-Cheng Mu Mon, 01 Dec 2008 22:03:42 +0000 http://wordpress.org/?v=2.6.2 By: Shin http://www.iis.sinica.edu.tw/~scm/2007/agda-exercise-proving-that-mergesort-returns-ordered-list/#comment-1872 Shin Tue, 27 May 2008 10:03:13 +0000 http://www.iis.sinica.edu.tw/~scm/?p=37#comment-1872 newsh (sorry for the late response), I think OList is a sorted list. Consider xs : OList 0. If xs is Nil, it is sorted. If xs equals, say, Cons 3 0≤3 ys, the tail ys must have type OList 3. Thus ys is lower-bounded by 3, not 0. newsh (sorry for the late response),

I think OList is a sorted list. Consider xs : OList 0. If xs is Nil, it is sorted. If xs equals, say, Cons 3 0≤3 ys, the tail ys must have type OList 3. Thus ys is lower-bounded by 3, not 0.

]]> By: newsh http://www.iis.sinica.edu.tw/~scm/2007/agda-exercise-proving-that-mergesort-returns-ordered-list/#comment-1801 newsh Thu, 15 May 2008 04:30:35 +0000 http://www.iis.sinica.edu.tw/~scm/?p=37#comment-1801 I think this only proves that the resulting list has a lower bound. You can construct arbitrary (unordered) lists of type (OList 0). The only restriction is that all elements are >= 0 (which is true by the definition of >=). I think this only proves that the resulting list has a lower bound. You can construct arbitrary (unordered) lists of type (OList 0). The only restriction is that all elements are >= 0 (which is true by the definition of >=).

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