diff --git a/tools/analyse.cpp b/tools/analyse.cpp
index 7a1fbf3..e38ae2d 100644
--- a/tools/analyse.cpp
+++ b/tools/analyse.cpp
@@ -13,7 +13,9 @@
 #include <cruft/util/view.hpp>
 #include <cruft/util/parse/value.hpp>
 
+#include <algorithm>
 #include <iostream>
+#include <compare>
 
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -28,6 +30,41 @@ enum {
 };
 
 
+//-----------------------------------------------------------------------------
+static
+std::strong_ordering
+region_ordering (
+    emory::chunk::region const &a,
+    emory::chunk::region const &b
+) {
+    if (auto const cmp = a.size () <=> b.size (); cmp != 0)
+        return cmp;
+    for (int i = 0; i < std::ssize (a.digest); ++i)
+        if (auto const cmp = a.digest[i] <=> b.digest[i]; cmp != 0)
+            return cmp;
+    return std::strong_ordering::equal;
+}
+
+
+static bool region_less (emory::chunk::region const &a, emory::chunk::region const &b)
+{
+    return region_ordering (a, b) < 0;
+}
+
+
+static bool region_equal (emory::chunk::region const &a, emory::chunk::region const &b)
+{
+    return region_ordering (a, b) == 0;
+}
+
+
+//static bool overlap (emory::chunk::region const &a, emory::chunk::region const &b)
+//{
+//    return a.offset.first < b.offset.second &&
+//           b.offset.first < a.offset.second;
+//}
+
+
 //-----------------------------------------------------------------------------
 int main (int argc, char const **argv)
 {