1.8 or
| (or expr expr expr ...) |
The exprs are evaluated from left to right. If the first
expr evaluates to true, the or expression
immediately evaluates to true. If the first expr
evaluates to false, the next expression is considered. If all
exprs evaluate to false, the or expression
evaluates to false. If any of the expressions evaluate to a
value other than true or false, it is an error.