Mercurial > cpdt > repo
diff src/Subset.v @ 271:aa3c054afce0
Some bug fixes while working on JFR version
author | Adam Chlipala <adamc@hcoop.net> |
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date | Mon, 19 Apr 2010 16:49:26 -0400 |
parents | c4b1c0de7af9 |
children | caa69851c78d |
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--- a/src/Subset.v Wed Feb 03 08:17:02 2010 -0500 +++ b/src/Subset.v Mon Apr 19 16:49:26 2010 -0400 @@ -71,7 +71,7 @@ (** We expand the type of [pred] to include a %\textit{%#<i>#proof#</i>#%}% that its argument [n] is greater than 0. When [n] is 0, we use the proof to derive a contradiction, which we can use to build a value of any type via a vacuous pattern match. When [n] is a successor, we have no need for the proof and just return the answer. The proof argument can be said to have a %\textit{%#<i>#dependent#</i>#%}% type, because its type depends on the %\textit{%#<i>#value#</i>#%}% of the argument [n]. -One aspects in particular of the definition of [pred_strong1] that may be surprising. We took advantage of [Definition]'s syntactic sugar for defining function arguments in the case of [n], but we bound the proofs later with explicit [fun] expressions. Let us see what happens if we write this function in the way that at first seems most natural. +One aspect in particular of the definition of [pred_strong1] may be surprising. We took advantage of [Definition]'s syntactic sugar for defining function arguments in the case of [n], but we bound the proofs later with explicit [fun] expressions. Let us see what happens if we write this function in the way that at first seems most natural. [[ Definition pred_strong1' (n : nat) (pf : n > 0) : nat :=