Moin, http://www.icme13.org <http://www.icme13.org/> https://www.conftool.pro/icme13/index.php?page=browseSessions&print=export&form_session=819 <https://www.conftool.pro/icme13/index.php?page=browseSessions&print=export&form_session=819> In this workshop, we propose to present the high-level programming language LISP as a tool for mathematical simulation and experimentation in a secondary mathematical educational environment. The computer algebra system Maxima was implemented using LISP language. We will introduce the fundamentals of the language and use it to study the “Impossible Problem”, as named by Martin Gardner in 1979. The purpose is to show some possibilities of how students can use this tool to investigate mathematical problems. It’s recommended to have a notebook or mobile device, with a Common LISP implementation, in order to better accomplish the activities. Gruß, Rainer