`Int -> ST m Int []` is incompatible with previous examples which use `Integer`. When using `Int` in the type of `makeAndIncrement`, you'll get something like this: ``` - + Errors (1) `-- ST.idr line 20 col 27: When checking right hand side of makeAndIncrement with expected type STrans m Int [] (\result => []) When checking an application of function Control.ST.>>=: Error in state transition: Operation has preconditions: [x ::: State Integer] States here are: [var ::: State Int] Operation has postconditions: \result => [x ::: State Integer] Required result states here are: st2_fn ```