diff --git a/sympy/series/order.py b/sympy/series/order.py index c55b345b41..01df175c68 100644 --- a/sympy/series/order.py +++ b/sympy/series/order.py @@ -275,7 +275,7 @@ def as_expr_variables(self, order_symbols): not all(p == self.point[0] for p in self.point): raise NotImplementedError('Order at points other than 0 ' 'or oo not supported, got %s as a point.' % point) - if order_symbols[0][1] != self.point[0]: + if order_symbols and order_symbols[0][1] != self.point[0]: raise NotImplementedError( "Multiplying Order at different points is not supported.") order_symbols = dict(order_symbols) diff --git a/sympy/series/tests/test_order.py b/sympy/series/tests/test_order.py index 189a7a30ae..393da39bc9 100644 --- a/sympy/series/tests/test_order.py +++ b/sympy/series/tests/test_order.py @@ -415,3 +415,7 @@ def test_order_subs_limits(): def test_issue_9351(): assert exp(x).series(x, 10, 1) == exp(10) + Order(x - 10, (x, 10)) + + +def test_issue_9192(): + assert O(1)*O(1) == O(1)