1 files changed, 27 insertions, 20 deletions

diff --git a/store/src/main/java/org/eclipse/viatra/solver/data/model/representation/TruthValue.java b/store/src/main/java/org/eclipse/viatra/solver/data/model/representation/TruthValue.java
index aeccde9e..049c7eac 100644
--- a/store/src/main/java/org/eclipse/viatra/solver/data/model/representation/TruthValue.java
+++ b/store/src/main/java/org/eclipse/viatra/solver/data/model/representation/TruthValue.java
@@ -1,42 +1,49 @@
 package org.eclipse.viatra.solver.data.model.representation;
 
-public class TruthValue {
-        public static final TruthValue True = new TruthValue("true");
-        public static final TruthValue False = new TruthValue("false");
-        public static final TruthValue Unknown = new TruthValue("unknown");
-        public static final TruthValue Error = new TruthValue("error");
-        
+public enum TruthValue {
+        TRUE("true"),
+
+        FALSE("false"),
+
+        UNKNOWN("unknown"),
+
+        ERROR("error");
+
         private final String name;
-        protected TruthValue(String name) {
+
+        private TruthValue(String name) {
                 this.name = name;
         }
-        
+
         public String getName() {
                 return name;
         }
-        
+
         public static TruthValue toTruthValue(boolean value) {
-                if(value) return True;
-                else return False;
+                return value ? TRUE : FALSE;
         }
+
         public boolean isConsistent() {
-                return this != Error;
+                return this != ERROR;
         }
+
         public boolean isComplete() {
-                return this != Unknown;
+                return this != UNKNOWN;
         }
+
         public boolean must() {
-                return this == True || this == Error;
+                return this == TRUE || this == ERROR;
         }
+
         public boolean may() {
-                return this == True || this == Unknown;
+                return this == TRUE || this == UNKNOWN;
         }
-        
+
         public TruthValue not() {
-                if(this == True) {
-                        return False;
-                } else if(this == False) {
-                        return True;
+                if (this == TRUE) {
+                        return FALSE;
+                } else if (this == FALSE) {
+                        return TRUE;
                 } else {
                         return this;
                 }