diff --git a/MathPad/MPExpression.h b/MathPad/MPExpression.h
index 977470e..6b8b1c8 100644
--- a/MathPad/MPExpression.h
+++ b/MathPad/MPExpression.h
@@ -22,8 +22,6 @@ extern NSString *MPDivisionOperator;
 #pragma mark Working With the Expression Tree
 
 @property (nonatomic, weak) MPFunction *parent; // Documentation: Do not set, may be nil
-- (void)functionSymbolChanged:(MPFunction *)symbol
-             atLocalIndexPath:(NSIndexPath *)indexPath; // Index path of change in symbol
 
 - (void)fixSymbols;
 
diff --git a/MathPad/MPExpression.m b/MathPad/MPExpression.m
index 63f9fd6..409bddf 100644
--- a/MathPad/MPExpression.m
+++ b/MathPad/MPExpression.m
@@ -50,14 +50,6 @@ NSString *MPDivisionOperator = @"/";
 
 #pragma mark Working With the Expression Tree
 
-- (void)functionSymbolChanged:(MPFunction *)symbol atLocalIndexPath:(NSIndexPath *)indexPath
-{
-    NSUInteger index = [_symbols indexOfObject:symbol];
-    if (index != NSNotFound) {
-        [self.parent childChanged:self atLocalIndexPath:[indexPath indexPathByAddingIndex:index]];
-    }
-}
-
 - (void)fixSymbols
 {
     _symbols = [self fixedSymbols:_symbols];
@@ -445,8 +437,12 @@ NSString *MPDivisionOperator = @"/";
     
     // Locate the position, split the symbols
     NSUInteger startIndex;
-    [self splitSymbolsAtLocation:range.location
-                  insertionIndex:&startIndex];
+    if ([self numberOfSymbols] == 0) {
+        startIndex = 0;
+    } else {
+        [self splitSymbolsAtLocation:range.location
+                      insertionIndex:&startIndex];
+    }
     
     // Perform the deletion
     if (range.length > 0) {
diff --git a/MathPad/MPFunction.h b/MathPad/MPFunction.h
index dc3b7b0..336ed3e 100644
--- a/MathPad/MPFunction.h
+++ b/MathPad/MPFunction.h
@@ -17,8 +17,6 @@
 #pragma mark Working With the Expression Tree
 
 @property (nonatomic, weak) MPExpression *parent; // Documentation: Do not set
-- (void)childChanged:(MPExpression *)child
-    atLocalIndexPath:(NSIndexPath *)indexPath;
 
 - (NSUInteger)numberOfChildren;
 - (MPExpression *)childAtIndex:(NSUInteger)index;
diff --git a/MathPad/MPFunction.m b/MathPad/MPFunction.m
index 6c6e2aa..d54e920 100644
--- a/MathPad/MPFunction.m
+++ b/MathPad/MPFunction.m
@@ -23,12 +23,6 @@
 
 #pragma mark Working With the Expression Tree
 
-- (void)childChanged:(MPExpression *)child atLocalIndexPath:(NSIndexPath *)indexPath
-{
-    [self.parent functionSymbolChanged:self
-                      atLocalIndexPath:[indexPath indexPathByAddingIndex:0]];
-}
-
 - (NSUInteger)numberOfChildren
 {
     return 0;