diff --git a/Yavsc.Abstract/IT/CodeFromChars.cs b/Yavsc.Abstract/IT/CodeFromChars.cs
new file mode 100644
index 00000000..cd1864cc
--- /dev/null
+++ b/Yavsc.Abstract/IT/CodeFromChars.cs
@@ -0,0 +1,62 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Yavsc.Abstract.IT
+{
+
+    public class CharArray : List<char>, IEnumerable<char>, IList<char>
+    {
+
+        public CharArray (char [] charArray) : base (charArray)
+        {
+
+        }
+        public CharArray (IList<char> word): base(word) {
+            
+        }
+        public CharArray (IEnumerable<char> word): base(word) {
+            
+        }
+
+        public IList<char> Aggregate(char other)
+        {
+             this.Add(other);
+             return this;
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+    }
+
+    public class CodeFromChars : List<CharArray>, ICode<char>
+    {
+        public void AddLetter(IEnumerable<char> letter)
+        {
+            var candide = new CharArray(letter);
+
+            // TODO build new denied letters: compute the automate
+
+            Add(candide);
+        }
+
+
+        public bool Validate()
+        {
+            throw new NotImplementedException();
+        }
+
+        IEnumerator<IEnumerable<char>> IEnumerable<IEnumerable<char>>.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/Yavsc.Abstract/IT/ICode.cs b/Yavsc.Abstract/IT/ICode.cs
index 925a7f9f..c190065a 100644
--- a/Yavsc.Abstract/IT/ICode.cs
+++ b/Yavsc.Abstract/IT/ICode.cs
@@ -1,22 +1,24 @@
 using System.Collections.Generic;
 
-namespace Yavsc
+namespace Yavsc.Abstract.IT
 {
-    public interface ILetter<T> : IEqualityComparer<T> {
-    }
-    public interface IWord<TLetter> where TLetter : ILetter<TLetter>
-    {
-        IWord<TLetter> Aggregate(TLetter other);
-    }
+    // un code est, parmis les ensembles de suites de signes,
+    // ceux qui n'ont qu'une seule suite de suites pouvant représenter toute suite de suite de signes
 
-    public interface ICode<TLetter> : IEnumerable<TLetter> where TLetter : ILetter<TLetter>
+    public interface ICode<TSign> : IEnumerable<IEnumerable<TSign>>
     {
         /// <summary>
-        /// Checks that (b!=c) => a.b != a.c
+        /// Checks false that a letter list combinaison correspond to another one
         /// </summary>
         /// <returns></returns>
         bool Validate();
 
-        IWord<TLetter> CreateWord(TLetter letter);
+        /// <summary>
+        /// Defines a new letter in this code, 
+        /// as an enumerable of <c>TLetter</c>
+        /// </summary>
+        /// <param name="letter"></param>
+        /// <returns></returns>
+        void AddLetter(IEnumerable<TSign> letter);
     }
 }
diff --git a/Yavsc.Server/Models/IT/Modeling/Code.cs b/Yavsc.Server/Models/IT/Modeling/Code.cs
deleted file mode 100644
index 378421b8..00000000
--- a/Yavsc.Server/Models/IT/Modeling/Code.cs
+++ /dev/null
@@ -1,39 +0,0 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
-
-namespace Yavsc.Models.IT.Modeling
-{
-    public abstract class Code<TLetter> : ICode<TLetter> where TLetter : ILetter<TLetter>
-    {
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            throw new NotImplementedException();
-        }
-
-        /// <summary>
-        /// !a Count^3 task len
-        /// </summary>
-        /// <returns></returns>
-        public bool Validate()
-        {
-            foreach  (var letter in this) {
-                    var word = this.CreateWord(letter);
-                foreach  (var other in this) {
-                    IWord<TLetter> first = word.Aggregate(other);
-                    foreach  (var tierce in this)
-                    {
-                        var otherword = word.Aggregate(tierce);
-                        if (first.Equals(otherword))
-                            return false;
-                    }
-                }
-            }
-            return true;
-        }
-
-        public abstract IEnumerator<TLetter> GetEnumerator();
-
-        public abstract IWord<TLetter> CreateWord(TLetter letter);
-    }
-}
diff --git a/Yavsc.Server/Models/IT/Modeling/Letter.cs b/Yavsc.Server/Models/IT/Modeling/Letter.cs
deleted file mode 100644
index 525c0eec..00000000
--- a/Yavsc.Server/Models/IT/Modeling/Letter.cs
+++ /dev/null
@@ -1,14 +0,0 @@
-
-namespace Yavsc.Models.IT.Modeling
-{
-    public abstract class Letter<T> : ILetter<T>
-    {
-        public abstract bool Equals(T x, T y);
-
-        public int GetHashCode(T obj)
-        {
-            return obj.GetHashCode();
-        }
-
-    }
-}