In terms of speed, yes. In terms of functionality, hell no. Compare the following in Racket: (define (add-2 x) (+ x 2)) (add-2 z) Where the result is

In terms of speed, yes. In terms of functionality, hell no. Compare the following in Racket: (define (add-2 x) (+ x 2)) (add-2 z) Where the result is an error without the possibility to provide a value. Compared to in SBCL: (defun add-2 (x) (+ x 2)) (add-2 z) Where we are dropped in the debugger with the following possible restarts: * Continue, where we retry the operation (best to first define z), * Use Value, where we can provide a value to use, * Store Value, where we can set z to a value and use the value, * Abort, where we just cancel the operation. There's also setf expansions, so in SBCL we can do, for example: (setf (car some-pair) 3) Whereas in Racket we can't do the equivalent: (set! (car some-pair) 3)