Correct total ordering and canonicalization

TUTORIAL.org

@@ -152,15 +152,22 @@ unique elements where ordering of items is unimportant.
 #set{flour, salt, water}
 #+END_SRC
 
-** Total ordering
+** Total ordering and canonicalization
 
 This is a good time to mention that even though from a semantic
 perspective sets and dictionaries do not carry information about the
 ordering of their elements (and Preserves doesn't care what order we
-enter them in for our hand-written-as-text Preserves documents), when
-serializing to binary data (or even when the Preserves library itself
-serializes to textual data), Preserves will always write out the
-elements in the same order, every time (aka, "total ordering").
+enter them in for our hand-written-as-text Preserves documents),
+Preserves has a well-defined "total ordering".
+
+*FULL WARNING:* the following claim is not implemented yet. :)
+Coming soon!
+
+Based on this total ordering, Preserves provides support for canonical
+ordering when serializing; in this mode, Preserves will always write
+out the elements in the same order, every time.
+When combined with binary serialization, this is Preserves' "canonical
+form".
 This is important and useful for many contexts, but especially for
 cryptographic signatures.
 
@@ -171,13 +178,16 @@ cryptographic signatures.
  cat: {"noise": "meow",
        "eats": #set{"kibble", "cat treats", "tinned meat"}}}
 
-@"Will always, always be written out in this order:"
+@"Will always, always be written out in this order when canonicalized:"
 {cat: {"eats": #set{"cat treats", "kibble", "tinned meat"},
        "noise": "meow"}
  monkey: {"eats": #set{"bananas", "berries"},
           "noise": "ooh-ooh"}}
 #+END_SRC
 
+This is a bit more expensive than normal serialization (because
+sorting needs to occur), but is still quite fast in general.
+
 ** Defining our own types using Records
 
 Finally, there is one more type that Preserves provides... but in a