Ciao Harm, Andrew, Aaron and David,
this is what I have been able to do adapting Harm code:
(the output formatting is not correct, just an example).
From my side it can be improved to make it more user friendly (maybe checking "start" etc.) but they are details.
I will spend some time to understand if the definition of x outside the define-scheme-function is the correct way to do (is this is a closure?)
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I read all the technical discussion, interesting but definitely too far from what I understand at the moment of the language.
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I didn't yet check the new code you sent Harm,
[harm code]