diff --git a/jedi/evaluate/precedence.py b/jedi/evaluate/precedence.py
index b96d80d6..22527c30 100644
--- a/jedi/evaluate/precedence.py
+++ b/jedi/evaluate/precedence.py
@@ -31,7 +31,7 @@ class PythonGrammar(object):
     EXPR = '|',
 
     COMPARISON = ('<', '>', '==', '>=', '<=', '!=', 'in',
-                  MultiPart('not', 'in'),  MultiPart('is', 'not')), 'is'
+                  MultiPart('not', 'in'), MultiPart('is', 'not')), 'is'
 
     NOT_TEST = 'not',
     AND_TEST = 'and',
@@ -58,7 +58,7 @@ class Precedence(object):
     def parse_tree(self, strip_literals=False):
         def process(which):
             try:
-                which = which.parse_tree
+                which = which.parse_tree()
             except AttributeError:
                 pass
             if strip_literals and isinstance(which, pr.Literal):
@@ -98,7 +98,12 @@ def _get_number(iterator, priority=PythonGrammar.LOWEST_PRIORITY):
 def _check_operator(iterator, priority=PythonGrammar.LOWEST_PRIORITY):
     """
     """
-    left = _get_number(iterator, priority)
+    try:
+        left = _get_number(iterator, priority)
+    except StopIteration:
+        _syntax_error(iterator.current, 'SyntaxError operand missing')
+        return None
+
     for el in iterator:
         if not isinstance(el, pr.Operator):
             _syntax_error(el)
@@ -127,5 +132,7 @@ def _check_operator(iterator, priority=PythonGrammar.LOWEST_PRIORITY):
         if operator is None:
             _syntax_error(el)
             continue
-        left = Precedence(left, operator, _check_operator(iterator, check_prio))
+        right = _check_operator(iterator, check_prio)
+        if right is not None:
+            left = Precedence(left, operator, right)
     return left
diff --git a/jedi/parser/__init__.py b/jedi/parser/__init__.py
index bf3db210..5c2b6e51 100644
--- a/jedi/parser/__init__.py
+++ b/jedi/parser/__init__.py
@@ -581,7 +581,7 @@ class Parser(object):
                 continue
             # default
             elif token_type in (tokenize.NAME, tokenize.STRING,
-                                tokenize.NUMBER) \
+                                tokenize.NUMBER, tokenize.OP) \
                     or tok_str in statement_toks:
                 # this is the main part - a name can be a function or a
                 # normal var, which can follow anything. but this is done
diff --git a/test/test_evaluate/test_precedence.py b/test/test_evaluate/test_precedence.py
index 7b1eb414..65c3e1a4 100644
--- a/test/test_evaluate/test_precedence.py
+++ b/test/test_evaluate/test_precedence.py
@@ -10,7 +10,10 @@ def parse_tree(statement_string):
     if isinstance(pr, precedence.Precedence):
         return pr.parse_tree(strip_literals=True)
     else:
-        return pr
+        try:
+            return pr.value  # Literal
+        except AttributeError:
+            return pr
 
 
 def test_simple():