Remove reference to compute in Tree

mapytex/calculus/core/tree.py

@@ -1,5 +1,3 @@
-#! /usr/bin/env python
-# -*- coding: utf-8 -*-
 # vim:fenc=utf-8
 #
 # Copyright © 2017 lafrite <lafrite@Poivre>
@@ -371,8 +369,7 @@ class Tree(object):
         ('+', (('*', (3, 4)), 2))
         >>> assert t.apply(to_nested) == nested_par
 
-        >>> from .compute import compute
-        >>> t.apply(compute)
+        >>> t.apply(lambda n, l, r: eval(str(l) + n + str(r)))
         14
 
         """