PEP 572: Fix a small issue found by Steve Dower, and clarify priority around commas.

pep-0572.rst

@@ -329,15 +329,20 @@ found in assignment statements:
 
 - Multiple targets are not directly supported::
 
-    x = y = z = 0  # Equivalent: (x := (y := (z := 0)))
+    x = y = z = 0  # Equivalent: (z := (y := (x := 0)))
 
-- Single assignment targets more complex than a single ``NAME`` are
+- Single assignment targets other than than a single ``NAME`` are
   not supported::
 
     # No equivalent
     a[i] = x
     self.rest = []
 
+- Priority around commas is different::
+
+    x = 1, 2  # Sets x to (1, 2)
+    (x := 1, 2)  # Sets x to 1
+
 - Iterable packing and unpacking (both regular or extended forms) are
   not supported::