-* Boolean Values:: Boolean values.
-* Missing Values in Expressions:: Using missing values in expressions.
-* Grouping Operators:: parentheses
-* Arithmetic Operators:: add sub mul div pow
-* Logical Operators:: AND NOT OR
-* Relational Operators:: EQ GE GT LE LT NE
-* Functions:: More-sophisticated operators.
-* Order of Operations:: Operator precedence.
+* Boolean Values:: Boolean values
+* Missing Values in Expressions:: Using missing values in expressions
+* Grouping Operators:: parentheses
+* Arithmetic Operators:: add sub mul div pow
+* Logical Operators:: AND NOT OR
+* Relational Operators:: EQ GE GT LE LT NE
+* Functions:: More-sophisticated operators
+* Order of Operations:: Operator precedence