<HTML><BODY>Why racket doesn't check arity when compiling? (define (test)   (car 12 3)) compiles and even runs. Ir raises an error only when test is called. I can have desirable result making (define-syntax car*   (make-set!-transformer    (λ (stx)      (syntax-case stx ()        [(car* x) (syntax-protect (syntax/loc stx (car x)))]        [(car* x ...) (raise-argument-error 'car "one argument" (syntax->datum #'(x ...)))]        [car* (syntax-protect (syntax/loc stx car))])))) (define (test)   (car* 12 3)) But it is cumbersome (I'll have to wrap every function) and I don't understand why compiler shouldn't see function contracts. -- Roman Klochkov</BODY></HTML>