As I play with an automapper for Dialog, I need to figure out the overall size of the map, to draw it appropriately. Assigning coordinates to the rooms is straightforward, but I’m realizing I don’t actually know how to find the minimum value of something.

For example, perhaps I have a predicate like `(room $Room is located at $X $Y $Z)`

, and I want to find the minimum X-value on the first floor (Z=1). I can iterate over all rooms with Z=1, and I can gather all their X-values with a `(collect $)`

predicate, but there doesn’t seem to be any straightforward way to find the *minimum* of them.

Is the best solution to collect them all into a list, then write my own `(minimum of $List into $Res)`

predicate?