diff --git a/src/models/formulas/meta/MetaDependencyFormula.java b/src/models/formulas/meta/MetaDependencyFormula.java
index b6fdd67..f3dcf08 100644
--- a/src/models/formulas/meta/MetaDependencyFormula.java
+++ b/src/models/formulas/meta/MetaDependencyFormula.java
@@ -33,4 +33,21 @@
 		return dependency.isMatchedBy(dep.getDependency(), binding, orderConstraint);
 	}
 
+	
+	public String toString() {
+		return dependency.toString();
+	}
+	
+	public boolean equals(Object another) {
+		if (! (another instanceof MetaDependencyFormula)) {
+			return false;
+		}
+		MetaDependencyFormula anohterFormula = (MetaDependencyFormula) another;
+		return dependency.equals(anohterFormula.getDependency());
+	}
+	
+	public int hashCode() {
+		return ("MDF" + toString()).hashCode();
+	}
+	
 }
diff --git a/src/models/formulas/meta/MetaEquationFormula.java b/src/models/formulas/meta/MetaEquationFormula.java
index e1ccf2f..9c4ddd9 100644
--- a/src/models/formulas/meta/MetaEquationFormula.java
+++ b/src/models/formulas/meta/MetaEquationFormula.java
@@ -40,5 +40,20 @@
 	}
 	
 	
+	public String toString() {
+		return leftSideHand.toString() + " = " + rightSideHand.toString();
+	}
+	
+	public boolean equals(Object another) {
+		if (! (another instanceof MetaEquationFormula)) {
+			return false;
+		}
+		MetaEquationFormula anohterFormula = (MetaEquationFormula) another;
+		return leftSideHand.equals(anohterFormula.getLeftSideHand()) && rightSideHand.equals(anohterFormula.getRightSideHand());
+	}
+	
+	public int hashCode() {
+		return ("MEF" + toString()).hashCode();
+	}
 	
 }
diff --git a/src/models/formulas/meta/MetaFormula.java b/src/models/formulas/meta/MetaFormula.java
index f21e2f8..949217f 100644
--- a/src/models/formulas/meta/MetaFormula.java
+++ b/src/models/formulas/meta/MetaFormula.java
@@ -16,4 +16,8 @@
 	
 	public abstract boolean isMatchedBy(Formula formula, Map<Variable, RDLTerm> binding, Map<Variable, OrderVariableConstraint> orderConstraint);
 	
+	public abstract String toString();
+	public abstract boolean equals(Object anohter);
+	public abstract int hashCode();
+	
 }