[plt-scheme] Where can I find documentation or example on pattern-matching with plt-match.ss

Good day, 

Chapter 31 of plt documentation are not clear for me. 

For example, the following code works with "match.ss" but not with
"plt-match.ss"

(require (lib "plt-match.ss"))
(define x (list 1 (list 23)))
(match x [(_ ((set! setit))) (setit 4)])

Thank you


Andre Mayers, Ph.D., professeur  |  tel: 819-821-8000x2041
Departement d'informatique       |  fax: 819-821-8200
Universite de Sherbrooke         |  andre.mayers at usherbrooke.ca
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