Minor tweaks

Author: javiereguiluz

reference/formats/expression_language.rst

@@ -425,32 +425,37 @@ Other Operators
 Operators Precedence
 ~~~~~~~~~~~~~~~~~~~~
 
-The following table summarize the operators and their associativity from the highest to the lowest precedence.
-It can be useful to understand the actual behavior of an expression.
-
-To avoid ambiguities it is a good practice to add parentheses.
-
-=============================================  =============
-Operators                                      associativity
-=============================================  =============
-``-``, ``+``                                   none
-``**``                                         right
-``*``, ``/``, ``%``                            left
-``not``, ``!``                                 none
-``~``                                          left
-``+``, ``-``                                   left
-``..``                                         left
-``==``, ``===``, ``!=``, ``!==``,              left
+Operator precedence determines the order in which operations are processed in an
+expression. For example, the result of the expression ``1 + 2 * 4`` is ``9``
+and not ``12`` because the multiplication operator (``*``) takes precedence over
+the addition operator (``+``).
+
+To avoid ambiguities (or to alter the default order of operations) add
+parentheses in your expressions (e.g. ``(1 + 2) * 4`` or ``1 + (2 * 4)``.
+
+The following table summarizes the operators and their associativity from the
+**highest to the lowest precedence**:
+
+=======================================================  =============
+Operators                                                associativity
+=======================================================  =============
+``-``, ``+`` (unary operators that add the number sign)  none
+``**``                                                   right
+``*``, ``/``, ``%``                                      left
+``not``, ``!``                                           none
+``~``                                                    left
+``+``, ``-``                                             left
+``..``                                                   left
+``==``, ``===``, ``!=``, ``!==``,                        left
 ``<``, ``>``, ``>=``, ``<=``,
 ``not in``, ``in``, ``contains``,
 ``starts with``, ``ends with``, ``matches``
-``&``                                          left
-``^``                                          left
-``|``                                          left
-``and``, ``&&``                                left
-``or``, ``||``                                 left
-=============================================  =============
-
+``&``                                                    left
+``^``                                                    left
+``|``                                                    left
+``and``, ``&&``                                          left
+``or``, ``||``                                           left
+=======================================================  =============
 
 Built-in Objects and Variables
 ------------------------------