Problem $1$: $($Exercise $7\mathrm{.}25$ of the Scott book$)$ In Example $7\mathrm{.}88$ we noted that functional languages can safely use reference counts since the lack of an assignment statement prevents them from introducing circularity. This isn't strictly true; constructs like Scheme's letrec can also be used to make cycles, so long as uses of circularly defined names are hidden inside lambda expressions in each definition