diff --git a/app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java b/app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
index da4a6273..33d61932 100644
--- a/app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
+++ b/app/src/main/java/org/solovyev/android/calculator/CalculatorImpl.java
@@ -472,15 +472,15 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
         if (TextUtils.isEmpty(text)) {
             return;
         }
-        final EntitiesRegistry<IConstant> varsRegistry = Locator.getInstance().getEngine().getVarsRegistry();
-        final IConstant ansVar = varsRegistry.get(VarsRegistry.ANS);
+        final EntitiesRegistry<IConstant> varsRegistry = Locator.getInstance().getEngine().getVariablesRegistry();
+        final IConstant ansVar = varsRegistry.get(VariablesRegistry.ANS);
 
         final Var.Builder builder = ansVar != null ? new Var.Builder(ansVar) : new Var.Builder();
-        builder.setName(VarsRegistry.ANS);
+        builder.setName(VariablesRegistry.ANS);
         builder.setValue(text);
         builder.setDescription(CalculatorMessages.getBundle().getString(CalculatorMessages.ans_description));
 
-        VarsRegistry.saveVariable(varsRegistry, builder, ansVar, this, false);
+        VariablesRegistry.saveVariable(varsRegistry, builder, ansVar, this, false);
     }
 
     @Subscribe
@@ -498,7 +498,7 @@ public class CalculatorImpl implements Calculator, CalculatorEventListener {
         switch (calculatorEventType) {
             case constant_changed:
                 final IConstant newConstant = ((Change<IConstant>) data).getNewValue();
-                if (!newConstant.getName().equals(VarsRegistry.ANS)) {
+                if (!newConstant.getName().equals(VariablesRegistry.ANS)) {
                     evaluate();
                 }
                 break;
diff --git a/app/src/main/java/org/solovyev/android/calculator/CalculatorUtils.java b/app/src/main/java/org/solovyev/android/calculator/CalculatorUtils.java
index 26e6c6a5..e3f05498 100644
--- a/app/src/main/java/org/solovyev/android/calculator/CalculatorUtils.java
+++ b/app/src/main/java/org/solovyev/android/calculator/CalculatorUtils.java
@@ -54,7 +54,7 @@ public final class CalculatorUtils {
         final Set<Constant> notSystemConstants = new HashSet<Constant>();
 
         for (Constant constant : expression.getConstants()) {
-            IConstant var = Locator.getInstance().getEngine().getVarsRegistry().get(constant.getName());
+            IConstant var = Locator.getInstance().getEngine().getVariablesRegistry().get(constant.getName());
             if (var != null && !var.isSystem() && !var.isDefined()) {
                 notSystemConstants.add(constant);
             }
diff --git a/app/src/main/java/org/solovyev/android/calculator/Engine.java b/app/src/main/java/org/solovyev/android/calculator/Engine.java
index 34fede7c..e0e5d052 100644
--- a/app/src/main/java/org/solovyev/android/calculator/Engine.java
+++ b/app/src/main/java/org/solovyev/android/calculator/Engine.java
@@ -54,7 +54,7 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
     @Nonnull
     private final MathEngine mathEngine;
     @Nonnull
-    private final VarsRegistry varsRegistry;
+    private final VariablesRegistry variablesRegistry;
 
     @Nonnull
     private final EntitiesRegistry<Operator> operatorsRegistry;
@@ -71,9 +71,9 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
     @Nonnull
     private String multiplicationSign = Preferences.multiplicationSign.getDefaultValue();
 
-    public Engine(@Nonnull MathEngine mathEngine, @Nonnull VarsRegistry varsRegistry, @Nonnull FunctionsRegistry functionsRegistry, @Nonnull EntitiesRegistry<Operator> operatorsRegistry, @Nonnull EntitiesRegistry<Operator> postfixFunctionsRegistry) {
+    public Engine(@Nonnull MathEngine mathEngine, @Nonnull VariablesRegistry variablesRegistry, @Nonnull FunctionsRegistry functionsRegistry, @Nonnull EntitiesRegistry<Operator> operatorsRegistry, @Nonnull EntitiesRegistry<Operator> postfixFunctionsRegistry) {
         this.mathEngine = mathEngine;
-        this.varsRegistry = varsRegistry;
+        this.variablesRegistry = variablesRegistry;
         this.functionsRegistry = functionsRegistry;
         this.operatorsRegistry = operatorsRegistry;
         this.postfixFunctionsRegistry = postfixFunctionsRegistry;
@@ -86,7 +86,7 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
         this.mathEngine.setRoundResult(true);
         this.mathEngine.setUseGroupingSeparator(true);
 
-        this.varsRegistry = new VarsRegistry(mathEngine.getConstantsRegistry(), new EntityDao<>("org.solovyev.android.calculator.CalculatorModel_vars", Vars.class, preferences));
+        this.variablesRegistry = new VariablesRegistry(mathEngine.getConstantsRegistry(), new EntityDao<>("org.solovyev.android.calculator.CalculatorModel_vars", Vars.class, preferences));
         this.operatorsRegistry = new OperatorsRegistry(mathEngine.getOperatorsRegistry());
         this.postfixFunctionsRegistry = new PostfixFunctionsRegistry(mathEngine.getPostfixFunctionsRegistry());
     }
@@ -106,8 +106,8 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
     }
 
     @Nonnull
-    public VarsRegistry getVarsRegistry() {
-        return varsRegistry;
+    public VariablesRegistry getVariablesRegistry() {
+        return variablesRegistry;
     }
 
     @Nonnull
@@ -169,7 +169,7 @@ public class Engine implements SharedPreferences.OnSharedPreferenceChangeListene
     }
 
     private void initAsync() {
-        init(varsRegistry);
+        init(variablesRegistry);
         init(functionsRegistry);
         init(operatorsRegistry);
         init(postfixFunctionsRegistry);
diff --git a/app/src/main/java/org/solovyev/android/calculator/ToJsclTextProcessor.java b/app/src/main/java/org/solovyev/android/calculator/ToJsclTextProcessor.java
index efd2b277..bd1a2551 100644
--- a/app/src/main/java/org/solovyev/android/calculator/ToJsclTextProcessor.java
+++ b/app/src/main/java/org/solovyev/android/calculator/ToJsclTextProcessor.java
@@ -114,9 +114,9 @@ public class ToJsclTextProcessor implements TextProcessor<PreparedExpression, St
             if (functionName == null) {
                 String operatorName = App.find(MathType.operator.getTokens(), startsWithFinder);
                 if (operatorName == null) {
-                    String varName = App.find(Locator.getInstance().getEngine().getVarsRegistry().getNames(), startsWithFinder);
+                    String varName = App.find(Locator.getInstance().getEngine().getVariablesRegistry().getNames(), startsWithFinder);
                     if (varName != null) {
-                        final IConstant var = Locator.getInstance().getEngine().getVarsRegistry().get(varName);
+                        final IConstant var = Locator.getInstance().getEngine().getVariablesRegistry().get(varName);
                         if (var != null) {
                             if (!var.isDefined()) {
                                 undefinedVars.add(var);
diff --git a/app/src/main/java/org/solovyev/android/calculator/VarsRegistry.java b/app/src/main/java/org/solovyev/android/calculator/VariablesRegistry.java
similarity index 94%
rename from app/src/main/java/org/solovyev/android/calculator/VarsRegistry.java
rename to app/src/main/java/org/solovyev/android/calculator/VariablesRegistry.java
index 69ddb3de..6a879979 100644
--- a/app/src/main/java/org/solovyev/android/calculator/VarsRegistry.java
+++ b/app/src/main/java/org/solovyev/android/calculator/VariablesRegistry.java
@@ -22,7 +22,6 @@
 
 package org.solovyev.android.calculator;
 
-import jscl.math.function.IConstant;
 import org.solovyev.android.calculator.model.EntityDao;
 import org.solovyev.android.calculator.model.MathEntityBuilder;
 import org.solovyev.android.calculator.model.Var;
@@ -31,12 +30,15 @@ import org.solovyev.common.JBuilder;
 import org.solovyev.common.math.MathEntity;
 import org.solovyev.common.math.MathRegistry;
 
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import java.util.HashMap;
 import java.util.Map;
 
-public class VarsRegistry extends BaseEntitiesRegistry<IConstant, Var> {
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import jscl.math.function.IConstant;
+
+public class VariablesRegistry extends BaseEntitiesRegistry<IConstant, Var> {
 
     @Nonnull
     public static final String ANS = "ans";
@@ -52,8 +54,8 @@ public class VarsRegistry extends BaseEntitiesRegistry<IConstant, Var> {
         substitutes.put("NaN", "nan");
     }
 
-    public VarsRegistry(@Nonnull MathRegistry<IConstant> mathRegistry,
-                        @Nonnull EntityDao<Var> entityDao) {
+    public VariablesRegistry(@Nonnull MathRegistry<IConstant> mathRegistry,
+                             @Nonnull EntityDao<Var> entityDao) {
         super(mathRegistry, "c_var_description_", entityDao);
     }
 
diff --git a/app/src/main/java/org/solovyev/android/calculator/function/EditFunctionFragment.java b/app/src/main/java/org/solovyev/android/calculator/function/EditFunctionFragment.java
index 72e0a189..97f75de3 100644
--- a/app/src/main/java/org/solovyev/android/calculator/function/EditFunctionFragment.java
+++ b/app/src/main/java/org/solovyev/android/calculator/function/EditFunctionFragment.java
@@ -60,7 +60,7 @@ import org.solovyev.android.calculator.KeyboardWindow;
 import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.ParseException;
 import org.solovyev.android.calculator.R;
-import org.solovyev.android.calculator.VarsRegistry;
+import org.solovyev.android.calculator.VariablesRegistry;
 import org.solovyev.android.calculator.math.edit.FunctionsActivity;
 import org.solovyev.android.calculator.math.edit.VarEditorSaver;
 import org.solovyev.android.calculator.view.EditTextCompat;
@@ -91,7 +91,7 @@ public class EditFunctionFragment extends BaseDialogFragment implements View.OnC
     private static final int MENU_CATEGORY = Menu.FIRST + 2;
 
     @NonNull
-    private final VarsRegistry constantsRegistry = Locator.getInstance().getEngine().getVarsRegistry();
+    private final VariablesRegistry constantsRegistry = Locator.getInstance().getEngine().getVariablesRegistry();
     @NonNull
     private final KeyboardWindow keyboardWindow = new KeyboardWindow();
     @NonNull
diff --git a/app/src/main/java/org/solovyev/android/calculator/math/MathType.java b/app/src/main/java/org/solovyev/android/calculator/math/MathType.java
index d54dd243..d756d7e6 100644
--- a/app/src/main/java/org/solovyev/android/calculator/math/MathType.java
+++ b/app/src/main/java/org/solovyev/android/calculator/math/MathType.java
@@ -170,7 +170,7 @@ public enum MathType {
         @Nonnull
         @Override
         public List<String> getTokens() {
-            return Locator.getInstance().getEngine().getVarsRegistry().getNames();
+            return Locator.getInstance().getEngine().getVariablesRegistry().getNames();
         }
 
         @Override
diff --git a/app/src/main/java/org/solovyev/android/calculator/math/edit/MathEntityRemover.java b/app/src/main/java/org/solovyev/android/calculator/math/edit/MathEntityRemover.java
index 3872e0ea..cd18e3d6 100644
--- a/app/src/main/java/org/solovyev/android/calculator/math/edit/MathEntityRemover.java
+++ b/app/src/main/java/org/solovyev/android/calculator/math/edit/MathEntityRemover.java
@@ -91,7 +91,7 @@ public class MathEntityRemover<T extends MathEntity> implements View.OnClickList
                                                                   @Nullable DialogInterface.OnClickListener callbackOnCancel,
                                                                   @Nonnull Context context,
                                                                   @Nonnull Object source) {
-        return new MathEntityRemover<IConstant>(constant, callbackOnCancel, false, Locator.getInstance().getEngine().getVarsRegistry(), context, source, Params.newConstantInstance());
+        return new MathEntityRemover<IConstant>(constant, callbackOnCancel, false, Locator.getInstance().getEngine().getVariablesRegistry(), context, source, Params.newConstantInstance());
     }
 
     /*
diff --git a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditDialogFragment.java b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditDialogFragment.java
index 6d15f61e..93323c73 100644
--- a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditDialogFragment.java
+++ b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditDialogFragment.java
@@ -163,7 +163,7 @@ public class VarEditDialogFragment extends DialogFragment implements CalculatorE
             }
         });
 
-        root.findViewById(R.id.save_button).setOnClickListener(new VarEditorSaver<IConstant>(varBuilder, constant, root, Locator.getInstance().getEngine().getVarsRegistry(), this));
+        root.findViewById(R.id.save_button).setOnClickListener(new VarEditorSaver<IConstant>(varBuilder, constant, root, Locator.getInstance().getEngine().getVariablesRegistry(), this));
 
         if (constant == null) {
             // CREATE MODE
diff --git a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditorSaver.java b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditorSaver.java
index b0c5935a..b53855de 100644
--- a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditorSaver.java
+++ b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarEditorSaver.java
@@ -28,7 +28,7 @@ import android.widget.EditText;
 import org.solovyev.android.calculator.EntitiesRegistry;
 import org.solovyev.android.calculator.Locator;
 import org.solovyev.android.calculator.R;
-import org.solovyev.android.calculator.VarsRegistry;
+import org.solovyev.android.calculator.VariablesRegistry;
 import org.solovyev.android.calculator.math.MathType;
 import org.solovyev.android.calculator.model.MathEntityBuilder;
 import org.solovyev.common.math.MathEntity;
@@ -145,7 +145,7 @@ public class VarEditorSaver<T extends MathEntity> implements View.OnClickListene
         if (error != null) {
             Locator.getInstance().getNotifier().showMessage(error, MessageType.error);
         } else {
-            VarsRegistry.saveVariable(mathRegistry, varBuilder, editedInstance, source, true);
+            VariablesRegistry.saveVariable(mathRegistry, varBuilder, editedInstance, source, true);
         }
     }
 }
diff --git a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarsFragment.java b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarsFragment.java
index eefad260..0a978a54 100644
--- a/app/src/main/java/org/solovyev/android/calculator/math/edit/VarsFragment.java
+++ b/app/src/main/java/org/solovyev/android/calculator/math/edit/VarsFragment.java
@@ -45,7 +45,7 @@ public class VarsFragment extends BaseEntitiesFragment<IConstant>implements Calc
 
     public static final String CREATE_VAR_EXTRA_STRING = "create_var";
     @NonNull
-    private final EntitiesRegistry<IConstant> registry = Locator.getInstance().getEngine().getVarsRegistry();
+    private final EntitiesRegistry<IConstant> registry = Locator.getInstance().getEngine().getVariablesRegistry();
 
     public VarsFragment() {
         super(CalculatorFragmentType.variables);
diff --git a/app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java b/app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java
index 4f54dd70..45742eca 100644
--- a/app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java
+++ b/app/src/test/java/org/solovyev/android/calculator/CalculatorTestUtils.java
@@ -23,8 +23,9 @@
 package org.solovyev.android.calculator;
 
 import android.content.Context;
+
 import com.squareup.otto.Bus;
-import jscl.JsclMathEngine;
+
 import org.junit.Assert;
 import org.mockito.Mockito;
 import org.robolectric.fakes.RoboSharedPreferences;
@@ -33,9 +34,12 @@ import org.solovyev.android.calculator.language.Languages;
 import org.solovyev.android.calculator.model.EntityDao;
 import org.solovyev.android.calculator.plot.CalculatorPlotter;
 
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.io.*;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.text.DecimalFormatSymbols;
 import java.util.HashMap;
 import java.util.Map;
@@ -43,6 +47,11 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import jscl.JsclMathEngine;
+
 /**
  * User: serso
  * Date: 10/7/12
@@ -94,12 +103,12 @@ public class CalculatorTestUtils {
 
         final JsclMathEngine jsclEngine = JsclMathEngine.getInstance();
 
-        final VarsRegistry varsRegistry = new VarsRegistry(jsclEngine.getConstantsRegistry(), entityDao);
+        final VariablesRegistry variablesRegistry = new VariablesRegistry(jsclEngine.getConstantsRegistry(), entityDao);
         final FunctionsRegistry functionsRegistry = new FunctionsRegistry(jsclEngine);
         final OperatorsRegistry operatorsRegistry = new OperatorsRegistry(jsclEngine.getOperatorsRegistry());
         final PostfixFunctionsRegistry postfixFunctionsRegistry = new PostfixFunctionsRegistry(jsclEngine.getPostfixFunctionsRegistry());
 
-        return new Engine(jsclEngine, varsRegistry, functionsRegistry, operatorsRegistry, postfixFunctionsRegistry);
+        return new Engine(jsclEngine, variablesRegistry, functionsRegistry, operatorsRegistry, postfixFunctionsRegistry);
     }
 
     public static void assertEval(@Nonnull String expected, @Nonnull String expression) {
diff --git a/app/src/test/java/org/solovyev/android/calculator/FromJsclSimplifyTextProcessorTest.java b/app/src/test/java/org/solovyev/android/calculator/FromJsclSimplifyTextProcessorTest.java
index 3406dcfc..1f042286 100644
--- a/app/src/test/java/org/solovyev/android/calculator/FromJsclSimplifyTextProcessorTest.java
+++ b/app/src/test/java/org/solovyev/android/calculator/FromJsclSimplifyTextProcessorTest.java
@@ -57,15 +57,15 @@ public class FromJsclSimplifyTextProcessorTest extends AbstractCalculatorTest {
         //Assert.assertEquals("e", tp.process("2.718281828459045"));
         //Assert.assertEquals("tee", tp.process("t2.718281828459045*2.718281828459045"));
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t2.718281828459045", "2"));
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t", (String) null));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t2.718281828459045", "2"));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t", (String) null));
         //Assert.assertEquals("t2.718281828459045e", tp.process("t2.718281828459045*2.718281828459045"));
         //Assert.assertEquals("ee", tp.process("2.718281828459045*2.718281828459045"));
         Assert.assertEquals("t×", tp.process("t*"));
         Assert.assertEquals("×t", tp.process("*t"));
         Assert.assertEquals("t2", tp.process("t*2"));
         Assert.assertEquals("2t", tp.process("2*t"));
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t", (String) null));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t", (String) null));
         Assert.assertEquals("t×", tp.process("t*"));
         Assert.assertEquals("×t", tp.process("*t"));
 
@@ -78,7 +78,7 @@ public class FromJsclSimplifyTextProcessorTest extends AbstractCalculatorTest {
         Assert.assertEquals("t^[2×2t]", tp.process("t^[2*2*t]"));
         Assert.assertEquals("2t^2[2t]", tp.process("2*t^2[2*t]"));
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("k", (String) null));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("k", (String) null));
         Assert.assertEquals("(t+2k)[k+2t]", tp.process("(t+2*k)*[k+2*t]"));
         Assert.assertEquals("(te+2k)e[k+2te]", tp.process("(t*e+2*k)*e*[k+2*t*e]"));
 
diff --git a/app/src/test/java/org/solovyev/android/calculator/model/AndroidEngineTest.java b/app/src/test/java/org/solovyev/android/calculator/model/AndroidEngineTest.java
index f08fb6f8..eb35a264 100644
--- a/app/src/test/java/org/solovyev/android/calculator/model/AndroidEngineTest.java
+++ b/app/src/test/java/org/solovyev/android/calculator/model/AndroidEngineTest.java
@@ -139,7 +139,7 @@ public class AndroidEngineTest extends AbstractCalculatorTest {
             cm.setAngleUnits(defaultAngleUnit);
         }
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("si", 5d));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("si", 5d));
         CalculatorTestUtils.assertEval("5", cm.evaluate("si"));
 
         CalculatorTestUtils.assertError("sin");
diff --git a/app/src/test/java/org/solovyev/android/calculator/model/EvaluateTest.java b/app/src/test/java/org/solovyev/android/calculator/model/EvaluateTest.java
index bdc550d0..36271e5e 100644
--- a/app/src/test/java/org/solovyev/android/calculator/model/EvaluateTest.java
+++ b/app/src/test/java/org/solovyev/android/calculator/model/EvaluateTest.java
@@ -116,7 +116,7 @@ public class EvaluateTest extends AbstractCalculatorTest {
         CalculatorTestUtils.assertError("(-1)i!");
         CalculatorTestUtils.assertEval("24i", "4!i");
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("si", 5d));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("si", 5d));
 
         try {
             cm.setAngleUnits(AngleUnit.rad);
@@ -130,14 +130,14 @@ public class EvaluateTest extends AbstractCalculatorTest {
             cm.setAngleUnits(defaultAngleUnit);
         }
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("s", 1d));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("s", 1d));
         CalculatorTestUtils.assertEval("5", cm.evaluate("si"));
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("k", 3.5d));
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("k1", 4d));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("k", 3.5d));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("k1", 4d));
         CalculatorTestUtils.assertEval("4", "k11");
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t", (String) null));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t", (String) null));
         CalculatorTestUtils.assertEval("11t", "t11");
         CalculatorTestUtils.assertEval("11et", "t11e");
         CalculatorTestUtils.assertEval("∞", "∞");
@@ -183,10 +183,10 @@ public class EvaluateTest extends AbstractCalculatorTest {
 			cm.setTimeout(3000);
 		}*/
 
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t", (String) null));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t", (String) null));
         CalculatorTestUtils.assertEval("2t", "∂(t^2,t)", JsclOperation.simplify);
         CalculatorTestUtils.assertEval("2t", "∂(t^2,t)");
-        Locator.getInstance().getEngine().getVarsRegistry().add(new Var.Builder("t", "2"));
+        Locator.getInstance().getEngine().getVariablesRegistry().add(new Var.Builder("t", "2"));
         CalculatorTestUtils.assertEval("2t", "∂(t^2,t)", JsclOperation.simplify);
         CalculatorTestUtils.assertEval("4", "∂(t^2,t)");