or

(or EXPRESSION EXPRESSION EXPRESSION ...)
An or expression contains two or more expressions. They are evaluated from left to right. If the first expression evaluates to true, the or expression immediately evaluates to true. If the first expression evaluates to false, the next expression is considered. If all expressions 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.

Reductions:
(or false ... true e ...) --> true
(or false ...) --> false
(or false ... v_1 e ...) e--> or: question result is not true or false
where v_1 is not true, and v_1 is not false

Beginning Student Language