Those look correct to me. The function returned by cons is just a switch that holds two values in a closure, and interprets what you pass it as a signal to det

Those look correct to me. The function returned by cons is just a switch that holds two values in a closure, and interprets what you pass it as a signal to determine which to retrieve. You could just as easily rewrite it to pass it 0 or 1 instead of car and cdr. If you evaluate (car (cons 1 2)) and (cdr (cons 1 2)) on paper using substitution, you'll see how it works.