diff --git a/core/src/main/java/org/nwapw/abacus/tree/NumberReducer.java b/core/src/main/java/org/nwapw/abacus/tree/NumberReducer.java
index 5ca1ee2..fcea885 100644
--- a/core/src/main/java/org/nwapw/abacus/tree/NumberReducer.java
+++ b/core/src/main/java/org/nwapw/abacus/tree/NumberReducer.java
@@ -8,6 +8,7 @@ import org.nwapw.abacus.function.TreeValueOperator;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.number.PromotionManager;
 import org.nwapw.abacus.number.PromotionResult;
+import org.nwapw.abacus.variables.VariableDatabase;
 
 /**
  * A reducer implementation that turns a tree into a single number.
@@ -35,7 +36,13 @@ public class NumberReducer implements Reducer<NumberInterface> {
         if (node instanceof NumberNode) {
             return abacus.getNumberImplementation().instanceForString(((NumberNode) node).getNumber());
         } else if (node instanceof VariableNode) {
-            return abacus.getVariableDatabase().getVariableValue(((VariableNode) node).getVariable());
+            VariableDatabase database = abacus.getVariableDatabase();
+            String name = ((VariableNode) node).getVariable();
+            NumberInterface variable = database.getVariables().get(name);
+            if(variable != null) return variable;
+            TreeNode definition = database.getDefinitions().get(name);
+            if(definition != null) return definition.reduce(this);
+            return abacus.getNumberImplementation().instanceForString("0");
         } else if (node instanceof NumberBinaryNode) {
             NumberInterface left = (NumberInterface) children[0];
             NumberInterface right = (NumberInterface) children[1];
diff --git a/core/src/main/kotlin/org/nwapw/abacus/variables/VariableDatabase.kt b/core/src/main/kotlin/org/nwapw/abacus/variables/VariableDatabase.kt
index ab477e2..405f26a 100644
--- a/core/src/main/kotlin/org/nwapw/abacus/variables/VariableDatabase.kt
+++ b/core/src/main/kotlin/org/nwapw/abacus/variables/VariableDatabase.kt
@@ -4,7 +4,7 @@ import org.nwapw.abacus.Abacus
 import org.nwapw.abacus.number.NumberInterface
 import org.nwapw.abacus.plugin.PluginListener
 import org.nwapw.abacus.plugin.PluginManager
-import javax.swing.tree.TreeNode
+import org.nwapw.abacus.tree.TreeNode
 
 /**
  * A database for variables and definition.
@@ -19,53 +19,11 @@ class VariableDatabase(val abacus: Abacus): PluginListener {
     /**
      * The variables that are stored in the database.
      */
-    private val variables = mutableMapOf<String, NumberInterface>()
+    val variables = mutableMapOf<String, NumberInterface>()
     /**
      * The definitions that are stored in the database.
      */
-    private val definitions = mutableMapOf<String, TreeNode>()
-
-    /**
-     * Stores a variable in the database.
-     *
-     * @param name the name of the variable.
-     * @param value the new value of the variable.
-     */
-    fun storeVariable(name: String, value: NumberInterface) {
-        variables[name] = value
-    }
-
-    /**
-     * Stores a definition in the database
-     *
-     * @param name the name of the definition.
-     * @param value the new value of the definition.
-     */
-    fun storeDefinition(name: String, value: TreeNode) {
-        definitions[name] = value
-    }
-
-    /**
-     * Gets the value of the variable, or 0 if
-     * it is not defined.
-     *
-     * @param name the name of the variable.
-     * @return the value of the variable.
-     */
-    fun getVariableValue(name: String): NumberInterface {
-        return variables[name] ?:
-                abacus.numberImplementation.instanceForString("0")
-    }
-
-    /**
-     * Gets the definition.
-     *
-     * @param name the name of the definition.
-     * @return the value of the definition, or null if one doesn't exist.
-     */
-    fun getDefinition(name: String): TreeNode? {
-        return definitions[name]
-    }
+    val definitions = mutableMapOf<String, TreeNode>()
 
     override fun onLoad(manager: PluginManager?) {