Index: reader.py
==================================================================
--- reader.py
+++ reader.py
@@ -1,6 +1,7 @@
 #!python3
+# Just a file for one-shot scripts
 
 import os
 import sys
 import re
 
@@ -15,20 +16,22 @@
             for sLine in hSrc:
                 yield sLine
     else:
         print("# Error: file not found.")
 
+# --------------------------------------------------------------------------------------------------
 
-def createFile (spfSrc, spfDst):
-    with open(spfDst, "w", encoding="utf-8") as hDst:
+def listUnknownWords (spf):
+    with open(spf+".res.txt", "w", encoding="utf-8") as hDst:
         for sLine in readFile(spfSrc):
             sLine = sLine.strip()
             if sLine:
                 for sWord in sLine.split():
                     if not oDict.isValid(sWord): 
                         hDst.write(sWord+"\n")
 
+# --------------------------------------------------------------------------------------------------
 
 def createLexStatFile (spf, dStat):
     dWord = {}
     for i, sLine in enumerate(readFile(spf)):
         if not sLine.startswith("#"):
@@ -50,15 +53,35 @@
             sWord, sCount = sLine.split()
             dStat[sWord] = dStat.get(sWord, 0) + int(sCount)
     return dStat
 
 
-def main ():
+def readStatFilesAndCreateLexicon ():
     dStat = {}
     readStatFile("stats1.txt", dStat)
     readStatFile("stats2.txt", dStat)
     readStatFile("stats3.txt", dStat)
     createLexStatFile("propositions.txt", dStat)
-    
+
+# --------------------------------------------------------------------------------------------------
+
+def isMoreThanOneSetInList (lSet):
+    aFirst = lSet.pop(0)
+    for aSet in lSet:
+        if aSet != aFirst:
+            return True
+    return False
+
+def filterLinesWithWordsWithDifferentStems (spf):
+    with open(spf+".res.txt", "w", encoding="utf-8") as hDst:
+        for sLine in readFile(spf):
+            lStemSet = [ set(oDict.stem(sWord))  for sWord in sLine.strip().split()]
+            if isMoreThanOneSetInList(lStemSet):
+                hDst.write(sLine)
+
+def filterHomophonicWords ():
+    filterLinesWithWordsWithDifferentStems("homophones.txt")
+
+# --------------------------------------------------------------------------------------------------
 
 if __name__ == '__main__' :
-    main()
+    filterHomophonicWords()