= += -= *= /= %= ^= **=
  | Assignment | 
?: | C conditional expression (nawk only) | 
|| | Logical OR (short-circuit) | 
&& | Logical AND (short-circuit) | 
in | Array membership (nawk only) | 
~  !~ | Match regular expression and negation | 
< <= > >= != == | Relational operators | 
| (blank) | Concatenation | 
+ - | Addition, subtraction | 
* / % | Multiplication, division, and modulus (remainder) | 
+ - ! | Unary plus and minus, and logical negation | 
^  ** | Exponentiation | 
++ --  | Increment and decrement, either prefix or postfix | 
$ | Field reference |