+1

diofant/calculus/order.py

@@ -114,22 +114,18 @@ def __new__(cls, expr, var=None, point=0, **kwargs):
 
         expr = expr.subs(s)
 
-        if expr.is_Add:
-            from ..core import expand_multinomial
-            expr = expand_multinomial(expr)
-
         if s:
-            new_var = tuple(rs)[0]
+            x = tuple(rs)[0]
         else:
-            new_var = var
+            x = var
 
         if expr.is_Add:
-            lst = expr.extract_leading_order([new_var])
+            lst = expr.extract_leading_order([x])
             expr = Add(*[f.expr for (e, f) in lst])
 
         elif expr:
-            expr = expr.as_leading_term(new_var)
-            expr = expr.as_independent(new_var, as_Add=False)[1]
+            expr = expr.as_leading_term(x)
+            _, expr = expr.as_independent(x, as_Add=False)
 
             expr = expand_power_base(expr)
             expr = expand_log(expr)
@@ -139,7 +135,6 @@ def __new__(cls, expr, var=None, point=0, **kwargs):
             # combine some power exponents (only "on top" of the
             # expression tree for f(x)), e.g.:
             # x**p * (-x)**q -> x**(p+q) for real p, q.
-            x = new_var
             margs = list(Mul.make_args(expr.as_independent(x, as_Add=False)[1]))
 
             for i, t in enumerate(margs):