Some other Scheme details:
* `#t` is true and `#f` is false
+ * `(lambda () ...)` constructs a thunk
+ * there is no difference in meaning between `[...]` and `(...)`; we just sometimes use the square brackets for clarity
* `'(1 . 2)` and `(cons 1 2)` are pairs (the same pair)
* `(list)` and `'()` both evaluate to the empty list
* `(null? lst)` tests whether `lst` is the empty list
* non-empty lists are implemented as pairs whose second member is a list
* `'()` `'(1)` `'(1 2)` `'(1 2 3)` are all lists
- * `(list)` `(list1)` `(list 1 2)` `(list 1 2 3)` are the same lists
- * `'(1 2 3)` and `(cons 1 '(2 3))` are pairs that are also lists (the same list)
+ * `(list)` `(list 1)` `(list 1 2)` `(list 1 2 3)` are the same lists
+ * `'(1 2 3)` and `(cons 1 '(2 3))` are both pairs and lists (the same list)
* `(pair? lst)` tests whether `lst` is a pair; if `lst` is a non-empty list, it will also pass this test; if `lst` fails this test, it may be because `lst` is the empty list, or because it's not a list or pair at all
* `(car lst)` extracts the first member of a pair / head of a list
* `(cdr lst)` extracts the second member of a pair / tail of a list
- * `(lambda () ...)` constructs a thunk
Here is the implementation: