From: Jim Pryor Date: Tue, 23 Nov 2010 13:51:15 +0000 (-0500) Subject: week9 tweak =/== X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=0050c659874a9453ce5b356d53464ac16e01945a;hp=a07a7e1719e637449177695d4f703d656b8e5ccb week9 tweak =/== Signed-off-by: Jim Pryor --- diff --git a/week9.mdwn b/week9.mdwn index a7385249..65c1084e 100644 --- a/week9.mdwn +++ b/week9.mdwn @@ -628,10 +628,10 @@ Programming languages tend to provide a bunch of mutation-related capabilities a Because of the particular way the numerical identity predicates are implemented in all of these languages, it doesn't quite match our conceptual expectations. For instance, For instance, if `ycell` is a reference cell, then `ref !ycell` will always be a numerically distinct reference cell containing the same value. We get this pattern of comparisons in OCaml: ycell == ycell - ycell != ref !ycell (* these aren't numerically identical *) + ycell != ref !ycell (* true, these aren't numerically identical *) ycell = ycell - ycell = ref !ycell (* they are qualitatively indiscernible *) + ycell = ref !ycell (* true, they are qualitatively indiscernible *) But now what about?