unbound variable

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unbound variable

Postby fluffhead » Thu Oct 08, 2015 4:01 am

I am trying to use two functions 'addtopowerset' and 'powerset' to get the power set of a list.
When I run the powerset function I get an error: unbound variable addtopowerset.
I don't understand why I am getting an error.

Here is my code:

(defun addtopowerset(x pset)
(append (list (list x))
(list (list(car pset)))
(list (cdr pset))
(list pset)
(list (cons x pset))
(list (cons x(list (car pset))))
(list (cons x(list (car (cdr pset)))))
(list (cons x(list (car (reverse pset)))))))

(defun powerset(lst)
((null lst) nil)
((funcall addtopowerset((car lst)(cdr lst))
(remove-duplicates (powerset(lst)) :test #'equal))
(powerset(cdr lst)))))
Posts: 1
Joined: Wed Oct 07, 2015 8:12 am

Re: unbound variable

Postby David Mullen » Thu Oct 08, 2015 2:18 pm

Don't use funcall to call the function directly. And on the remove-duplicates line in the powerset function, the reference to LST shouldn't be in parentheses by itself.
David Mullen
Posts: 56
Joined: Mon Dec 01, 2014 12:29 pm

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