When everything works and good definitions and examples just flow naturally and the other person seems to be learning everything you're saying.
I don't have anything particular to say, except the fact that the work from the previous weeks seems to be paying off, over all giving her a method improved dramatically the way she deals with implementing functions from scratch. Also, doing exercises as we go in the book it's way more effective than having her solve them on her own.
They are way too difficult. I've slowed the pace considerably due to a misjudgement of exercises difficulty.
On giving a method
It was her who raised this point and it actually makes a lot of sense, it's a shame I didn't think about this earlier on.
There was some confusion on how to use functions and recursion in the end. I didn't spot that previously. I am starting to think that a lot of what "being a teacher" means is to understand when your audience got the idea you're trying to pass on.
So what didn't I understand? For sure the fact that going from
|;; in the previous solution we implemented 2nd and last|
|;; but we did not define proper return values for the edge cases,|
|;; this time we will|
|;; your task will be to provide those values, as you can imagine|
|;; (sum 4 'gatto) does not have an answer|
|;; make it so that expressions will return true|
|;; a suggestion would be to paste the definitions of 2nd and last|
|;; above the exercises and fix the errors you get, by returning proper values|
From the previous lesson
It wasn't clear, and still isn't to me as of now, how S-exps are counted in a list, for example
;; how many are here? Is it 2? (((a b c) d))