(write (or 1))
(newline)
(write (or #f 2))
(newline)
(write (or 3 #t))
(newline)

(let ((tmp 4))
  (write (or #f tmp))
  (newline))

(write
 (letrec-syntax
     ((myor
       (er-macro-transformer
        (lambda (expr rename compare)
          (if (null? (cdr expr))
              #f
              (list (rename 'let) (list (list (rename 'tmp) (cadr expr)))
                    (list (rename 'if) (rename 'tmp)
                          (rename 'tmp)
                          (cons (rename 'myor) (cddr expr)))))))))
   (let ((tmp 5)) (myor #f tmp))))
(newline)