syntax-error

Correct! The problem is in the line right after that, where it says ((cons nil lst) (append lst nil) (insertat nil lst 3) … The issue is the two opening parentheses. Parentheses can change meaning in special contexts (like the cond form you’re using), but in this context, the parentheses signify regular function application, just … Read more

What you are missing is that in Lisp parentheses are meaningful. In C/Java/Python &c, the following expressions are the same: a+b (a+b) (a)+(b) (((a)+(b))) (((((a)+(b))))) In Lisp, the following expressions are very different: a — a symbol (a) — a list with a single element, which is the symbol a (1 (2)) — a list … Read more