Index: src/natools-smaz-tools.adb
==================================================================
--- src/natools-smaz-tools.adb
+++ src/natools-smaz-tools.adb
@@ -675,10 +675,32 @@
             Index := Index + Verbatim_Length + 1;
          end if;
       end loop;
    end Evaluate_Dictionary_Partial;
 
+
+   procedure Filter_By_Count
+     (Counter : in out Word_Counter;
+      Threshold_Count : in String_Count)
+   is
+      Position, Next : Word_Maps.Cursor;
+   begin
+      Position := Word_Maps.First (Counter.Map);
+
+      while Word_Maps.Has_Element (Position) loop
+         Next := Word_Maps.Next (Position);
+
+         if Word_Maps.Element (Position) < Threshold_Count then
+            Word_Maps.Delete (Counter.Map, Position);
+         end if;
+
+         Position := Next;
+      end loop;
+
+      pragma Assert (for all Count of Counter.Map => Count >= Threshold_Count);
+   end Filter_By_Count;
+
 
    function Simple_Dictionary
      (Counter : in Word_Counter;
       Word_Count : in Natural)
      return String_Lists.List

Index: src/natools-smaz-tools.ads
==================================================================
--- src/natools-smaz-tools.ads
+++ src/natools-smaz-tools.ads
@@ -113,10 +113,15 @@
       Max_Size : in Positive);
       --  Add the "words" from Phrase into Counter, with a word being currently
       --  defined as anything between ASCII blanks or punctuation,
       --  or in other words [0-9A-Za-z\x80-\xFF]+
 
+   procedure Filter_By_Count
+     (Counter : in out Word_Counter;
+      Threshold_Count : in String_Count);
+      --  Remove from Counter all entries whose count is below the threshold
+
    function Simple_Dictionary
      (Counter : in Word_Counter;
       Word_Count : in Natural)
      return String_Lists.List;
       --  Return the Word_Count words in Counter that have the highest score,