X-Git-Url: https://git.distorted.org.uk/~mdw/fringe/blobdiff_plain/2bd37ef118cb1e41cb0e9e2332a9eb69ac2f2df4..6bce693f147dfca5affdeb04f93a41b7ebd76bb9:/f%23-fringe.fs

diff --git a/f#-fringe.fs b/f#-fringe.fs
index efcc860..45d011b 100644
--- a/f#-fringe.fs
+++ b/f#-fringe.fs
@@ -1,4 +1,4 @@
-/// -*-f#-mode-*-
+/// -*-fsharp-mode-*-
 ///
 /// F# implementation of a `same-fringe' solver.
 
@@ -41,16 +41,11 @@ let list_iterator it = it |> fold_iterator (curry List.Cons) [] |> List.rev
 // Asnwer whether two iterators report the same items.
 let rec same_iterators_p ita itb =
   match next ita with
-    | None ->
-      match next itb with
-        | None -> true
-        | _ -> false
+    | None -> Option.isNone(next itb)
     | Some (a, ita) ->
       match next itb with
-        | None -> false
-        | Some (b, itb) ->
-          if a = b then same_iterators_p ita itb
-          else false
+        | Some (b, itb) when a = b -> same_iterators_p ita itb
+        | _ -> false
 
 ///--------------------------------------------------------------------------
 /// Nodes and trees.