diff --git a/.gitignore b/.gitignore
index 1b6985c..2fd3480 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,8 @@
 
 # Ignore Gradle build output directory
 build
+
+.vscode
+.idea
+
+output.puml
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index 4f19f0e..187d39d 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -22,6 +22,9 @@ dependencies {
 
     // This dependency is used by the application.
     implementation 'com.google.guava:guava:31.1-jre'
+
+    // uml
+    implementation 'com.github.javaparser:javaparser-symbol-solver-core:3.26.2'
 }
 
 application {
diff --git a/app/src/main/java/sudoku/Bloc.java b/app/src/main/java/sudoku/Bloc.java
index 39f1e90..ab3636f 100644
--- a/app/src/main/java/sudoku/Bloc.java
+++ b/app/src/main/java/sudoku/Bloc.java
@@ -1,14 +1,16 @@
 package sudoku;
 
-public class Bloc<S> {
+import java.util.List;
 
-	private final Case<S>[] cases;
+public class Bloc {
 
-	public Bloc(Case<S>[] cases) {
+	private final List<Case> cases;
+
+	public Bloc(List<Case> cases) {
 		this.cases = cases;
 	}
 
-	public Case<S>[] getCases() {
+	public List<Case> getCases() {
 		return cases;
 	}
 
diff --git a/app/src/main/java/sudoku/Case.java b/app/src/main/java/sudoku/Case.java
index 17dc143..7f340ad 100644
--- a/app/src/main/java/sudoku/Case.java
+++ b/app/src/main/java/sudoku/Case.java
@@ -1,18 +1,46 @@
 package sudoku;
 
-public class Case<S> {
+public class Case {
 
-	private Symbole<S> symbole;
+	private static int NOSYMBOLE = -1;
+	private int symboleIndex;
+	private Bloc bloc = null;
 
-	public Case(Symbole<S> symbole) {
-		this.symbole = symbole;
+	public Case(int symboleIndex) {
+		this.symboleIndex = symboleIndex;
 	}
 
-	public Symbole<S> getSymbole() {
-		return this.symbole;
+	/**
+	 * @brief Default constructor, empty square
+	 */
+	public Case() {
+		this(NOSYMBOLE);
 	}
 
-	public void setSymbole(Symbole<S> symbole) {
-		this.symbole = symbole;
+	public int getSymboleIndex() {
+		return symboleIndex;
+	}
+
+	public void setSymboleIndex(int symboleIndex) {
+		this.symboleIndex = symboleIndex;
+	}
+
+	public void clear() {
+		setSymboleIndex(NOSYMBOLE);
+	}
+
+	public Bloc getBloc() {
+		return this.bloc;
+	}
+
+	void setBloc(Bloc bloc) {
+		this.bloc = bloc;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj instanceof Case autreCase)
+			return autreCase.getSymboleIndex() == this.getSymboleIndex();
+		return super.equals(obj);
 	}
 }
diff --git a/app/src/main/java/sudoku/Main.java b/app/src/main/java/sudoku/Main.java
index 7479a56..0084166 100644
--- a/app/src/main/java/sudoku/Main.java
+++ b/app/src/main/java/sudoku/Main.java
@@ -10,5 +10,6 @@ public class Main {
 
     public static void main(String[] args) {
         System.out.println(new Main().getGreeting());
+        // var test = SudokuFactory.createBasicEmptySudoku(9);
     }
 }
diff --git a/app/src/main/java/sudoku/MultiDoku.java b/app/src/main/java/sudoku/MultiDoku.java
index 7561ad1..ac64057 100644
--- a/app/src/main/java/sudoku/MultiDoku.java
+++ b/app/src/main/java/sudoku/MultiDoku.java
@@ -1,6 +1,5 @@
 package sudoku;
 
-import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -8,12 +7,12 @@ import java.util.List;
  * @brief Représente une grille de Multidoku.
  *        Une grille de sudoku est un multidoku avec un seul sous-sudoku
  */
-public class MultiDoku<S> {
+public class MultiDoku {
 
-	private final List<Sudoku<S>> sousGrilles;
+	private final List<Sudoku> sousGrilles;
 
-	public MultiDoku(List<Symbole<S>> symboles) {
-		this.sousGrilles = new ArrayList<>();
+	public MultiDoku(List<Sudoku> sousGrilles) {
+		this.sousGrilles = sousGrilles;
 	}
 
 }
diff --git a/app/src/main/java/sudoku/Sudoku.java b/app/src/main/java/sudoku/Sudoku.java
index a5d8567..da29fba 100644
--- a/app/src/main/java/sudoku/Sudoku.java
+++ b/app/src/main/java/sudoku/Sudoku.java
@@ -1,27 +1,36 @@
 package sudoku;
 
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 /**
  * @class Sudoku
  * @brief Représente une grille de sudoku avec N symboles
  */
-public class Sudoku<S> {
+public class Sudoku {
 
-	private final List<Symbole<S>> symboles;
-	private final List<Bloc<S>> blocs;
-	private final List<Case<S>> cases;
+	private final List<Bloc> blocs;
+	private final List<Case> cases;
 
-	public Sudoku(List<Symbole<S>> symboles) {
-		this.symboles = symboles;
-		// initialisation des cases
-		this.cases = new ArrayList<>(this.symboles.size() * this.symboles.size());
-		Collections.fill(this.cases, new Case<>(null));
-		// initialisation des blocs
-		this.blocs = new ArrayList<>(this.symboles.size());
-		Collections.fill(this.blocs, new Bloc<>(null));
+	public Sudoku(List<Case> cases, List<Bloc> blocs) {
+		// assert(symbolCount >= 2);
+		// // initialisation des cases
+		// this.cases = new ArrayList<>(symbolCount * symbolCount);
+		// Collections.fill(this.cases, new Case());
+		// // initialisation des blocs
+		// this.blocs = new ArrayList<>(symbolCount);
+		// Collections.fill(this.blocs, new Bloc(null));
+		this.cases = cases;
+		this.blocs = blocs;
+	}
+
+	public Case getCase(int x, int y) {
+		int index = y * getSize() + x;
+		assert(index < getSize() * getSize());
+		return this.cases.get(index);
+	}
+
+	public int getSize() {
+		return this.blocs.size();
 	}
 
 }
diff --git a/app/src/main/java/sudoku/Symbole.java b/app/src/main/java/sudoku/Symbole.java
deleted file mode 100644
index fd51d68..0000000
--- a/app/src/main/java/sudoku/Symbole.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package sudoku;
-
-public class Symbole<S> {
-
-	private final S valeur;
-
-	public Symbole(S valeur) {
-		this.valeur = valeur;
-	}
-
-	public S getValeur() {
-		return valeur;
-	}
-
-}
diff --git a/app/src/main/java/sudoku/constraint/BlockConstraint.java b/app/src/main/java/sudoku/constraint/BlockConstraint.java
new file mode 100644
index 0000000..dc537e1
--- /dev/null
+++ b/app/src/main/java/sudoku/constraint/BlockConstraint.java
@@ -0,0 +1,15 @@
+package sudoku.constraint;
+
+import sudoku.Bloc;
+import sudoku.Case;
+import sudoku.Sudoku;
+
+public class BlockConstraint implements IConstraint{
+
+	@Override
+	public boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex) {
+		Bloc bloc = s.getCase(x, y).getBloc();
+		return !bloc.getCases().contains(new Case(newSymbolIndex));
+	}
+
+}
diff --git a/app/src/main/java/sudoku/constraint/ColumnConstraint.java b/app/src/main/java/sudoku/constraint/ColumnConstraint.java
new file mode 100644
index 0000000..ef71445
--- /dev/null
+++ b/app/src/main/java/sudoku/constraint/ColumnConstraint.java
@@ -0,0 +1,16 @@
+package sudoku.constraint;
+
+import sudoku.Sudoku;
+
+public class ColumnConstraint implements IConstraint {
+
+	@Override
+	public boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex) {
+		for (int i = 0; i < s.getSize(); i++) {
+			if (s.getCase(x, newSymbolIndex).getSymboleIndex() == newSymbolIndex)
+				return false;
+		}
+		return true;
+	}
+
+}
diff --git a/app/src/main/java/sudoku/constraint/IConstraint.java b/app/src/main/java/sudoku/constraint/IConstraint.java
new file mode 100644
index 0000000..3d7fca9
--- /dev/null
+++ b/app/src/main/java/sudoku/constraint/IConstraint.java
@@ -0,0 +1,22 @@
+package sudoku.constraint;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import sudoku.Sudoku;
+
+public interface IConstraint {
+
+	boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex);
+
+	default List<Integer> getPossibleSymbols(final Sudoku s, int x, int y) {
+		List<Integer> possibilities = new ArrayList<>();
+		for (int i = 0; i < s.getSize(); i++) {
+			if (canBePlaced(s, x, y, i)) {
+				possibilities.add(i);
+			}
+		}
+		return possibilities;
+	}
+
+}
diff --git a/app/src/main/java/sudoku/constraint/LineConstraint.java b/app/src/main/java/sudoku/constraint/LineConstraint.java
new file mode 100644
index 0000000..f6836cd
--- /dev/null
+++ b/app/src/main/java/sudoku/constraint/LineConstraint.java
@@ -0,0 +1,16 @@
+package sudoku.constraint;
+
+import sudoku.Sudoku;
+
+public class LineConstraint implements IConstraint {
+
+	@Override
+	public boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex) {
+		for (int i = 0; i < s.getSize(); i++) {
+			if (s.getCase(newSymbolIndex, y).getSymboleIndex() == newSymbolIndex)
+				return false;
+		}
+		return true;
+	}
+
+}
diff --git a/java2plantuml.jar b/java2plantuml.jar
new file mode 100644
index 0000000..a81680d
Binary files /dev/null and b/java2plantuml.jar differ