diff options
| author | Masaya Tojo <masaya@tojo.tokyo> | 2021-01-28 04:30:52 +0900 |
|---|---|---|
| committer | Masaya Tojo <masaya@tojo.tokyo> | 2021-01-28 04:30:52 +0900 |
| commit | 2a3e2ef7aab64575dfb382d2e85c31458b05b366 (patch) | |
| tree | 7eb3952b49bcbf32c8112a7e5b0087f966f72530 | |
| parent | bab1b891995a3f78e194cedbb5dd73dec2b3f6ed (diff) | |
Use `nat-listp` function.
| -rw-r--r-- | blackjack.lisp | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/blackjack.lisp b/blackjack.lisp index 2792046..47a5c20 100644 --- a/blackjack.lisp +++ b/blackjack.lisp @@ -38,15 +38,8 @@ (cons (car x) (filter-natp (cdr x)))) (t (filter-natp (cdr x))))) -(defun nat-list-p (x) - (declare (xargs :guard t)) - (cond ((consp x) - (and (natp (car x)) - (nat-list-p (cdr x)))) - (t (null x)))) - (defun sum (x) - (declare (xargs :guard (nat-list-p x))) + (declare (xargs :guard (nat-listp x))) (cond ((endp x) 0) (t (+ (car x) (sum (cdr x)))))) |