| name | predicate? | procedure |
|---|---|---|
| symbol | expression | expression |
| symbol | expression | expression |
| nary1 | (lambda (a) (not (null? a))) | identity |
| nary | (lambda (a) #t) | identity |
| boolean |
(lambda (a)
(or (null? a)
(and (pair? a)
(null? (cdr a))
(boolean? (car a)))))
|
(lambda (a) (if (null? a) #f (car a))) |
| optional |
(lambda (lambda
(a)
(or (null? a) (and (pair? a) (null? (cdr a))))))
|
identity |
| single | (lambda (a) (and (pair? a) (null? (cdr a)))) | car |