diff --git a/mapytex/calculus/core/tree.py b/mapytex/calculus/core/tree.py
index 79c81fb..013d449 100644
--- a/mapytex/calculus/core/tree.py
+++ b/mapytex/calculus/core/tree.py
@@ -182,7 +182,7 @@ class Tree(object):
 
         return cls(node, l_value, r_value)
 
-    def map_leaf(self, function):
+    def map_on_leaf(self, function):
         """ Map on leafs a function
 
         :param function: take leaf value returns other value
@@ -200,7 +200,7 @@ class Tree(object):
          | > 3
          | > 4
          > 2
-        >>> print(t.map_leaf(lambda x:2*x))
+        >>> print(t.map_on_leaf(lambda x:2*x))
         +
          > *
          | > 6
@@ -209,19 +209,19 @@ class Tree(object):
 
         """
         try:
-            left_applied = self.left_value.map_leaf(function)
+            left_applied = self.left_value.map_on_leaf(function)
         except AttributeError:
             left_applied = function(self.left_value)
 
         try:
-            right_applied = self.right_value.map_leaf(function)
+            right_applied = self.right_value.map_on_leaf(function)
         except AttributeError:
             right_applied = function(self.right_value)
 
         return Tree(self.node, left_applied, right_applied)
 
-    def apply_on_last_branches(self, function):
-        """ Apply the function on last branches before leaf.
+    def apply_on_last_level(self, function):
+        """ Apply the function on last level of the tree before leaf
 
         :param function: (op, a, a) -> b
         :returns: b if it is a 1 level Tree, Tree otherwise
@@ -240,7 +240,7 @@ class Tree(object):
          | > 4
          > 2
         >>> from .tree_tools import infix_str_concatenate
-        >>> tt = t.apply_on_last_branches(lambda *x: infix_str_concatenate(*x))
+        >>> tt = t.apply_on_last_level(lambda *x: infix_str_concatenate(*x))
         >>> print(tt)
         +
          > 3 * 4
@@ -250,13 +250,13 @@ class Tree(object):
         left_is_leaf = 0
         right_is_leaf = 0
         try:
-            left_applied = self.left_value.apply_on_last_branches(function)
+            left_applied = self.left_value.apply_on_last_level(function)
         except AttributeError:
             left_applied = self.left_value
             left_is_leaf = 1
 
         try:
-            right_applied = self.right_value.apply_on_last_branches(function)
+            right_applied = self.right_value.apply_on_last_level(function)
         except AttributeError:
             right_applied = self.right_value
             right_is_leaf = 1
@@ -267,7 +267,7 @@ class Tree(object):
             return Tree(self.node, left_applied, right_applied)
 
     def apply(self, function):
-        """ Apply the function to the whole tree
+        """ Apply the function on every node of the tree
 
         :param function: (op, a, a) -> b
         :returns: b