entering and exiting

enter (entering): enter X, get in/into X, climb in/into X, go in/into X, board X, get on X. One gate: the target needs the enterable trait; anything else refuses with not_enterable (checked in the action: parse by syntax, refuse by world, since ADR-231). A closed openable refuses with container_closed; if you are already inside, it refuses with already_inside. The trait's one setting, its preposition, decides whether you are in the bathtub or on the park bench (entered vs entered_on); on is a TypeScript setting today. There is no occupancy limit; too_full is reserved but never fires.

exit (exiting): bare exit, leave, get out, go out, climb out, disembark, alight. A named target parses too (exit the chair), and naming something you aren't inside refuses with not_in_that (ADR-231). EXIT undoes an ENTER: out of the container, off the supporter. Standing in a plain room refuses with already_outside; leaving rooms is GO's job. A closed openable container refuses with container_closed: you can shut yourself in.

The author writes:

create the Laundry
  a room

  Copper tubs, drying racks, and a mangle with an evil reputation.

create the laundry chest
  aka chest
  a container, enterable, openable, starts open
  in the Laundry

  A wicker chest big enough to hide in.

create the mangle
  scenery
  in the Laundry

  Two iron rollers and a crank. Keep your fingers clear.

create the player
  starts in the Laundry

The player sees:

> enter the mangle
You can't enter the mangle.

> get into the chest
You get into the laundry chest.

> close the chest
You close the laundry chest.

> exit
The laundry chest is closed.

> open the chest
You open the laundry chest.

Inside the laundry chest you see yourself.

> exit
You get out of the laundry chest.

> exit the chest
But you aren't in the laundry chest.

> exit
You're not inside anything.

One trait draws the line (the mangle turns you away, the chest lets you in), and the composed openable makes the lid real: closed, it holds you until you open it from the inside (revealing, honestly, yourself).

Cross-references: climb into X is entering and climb out is exiting; the enterable trait and the vehicle trait that rides on it are documented separately.