intfiction.org

Test room is a room.
Bob is a man.
Anne is a woman.
Jim is a man.
Bob, Anne, and Jim are in test room.

Watch is a kind of thing. Ring is a kind of thing.
Bob's watch is a watch. Bob's watch is a part of Bob.
Anne's watch is a watch. Anne's watch is a part of Anne.
Anne's ring is a ring. Anne is holding Anne's ring.
Jim's ring is a ring. Jim's ring is in test room.
Understand "band", "circlet", "loop", or "ringlet" as ring.

Instead of examining a man:
   say "His name is [printed name of item described]."
Instead of examining a woman:
   say "Her name is [printed name of item described]."
Instead of examining player:
   say "Your name is [printed name of item described]."

Body switcher is a device.
Instead of switching on body switcher:
   if player is Bob:
      now player is Anne;
      now anne is holding the body switcher;
   otherwise:
      now player is Bob;
      now bob is holding the body switcher.

The player is bob. Bob is holding the switcher.

Ownership relates one person to many things. The verb to own [conjugations etc.] implies the ownership relation.
When play begins:
   repeat with item running through things enclosed by a person:
       now a random person enclosing item owns item;
   now Jim owns Jim's ring. [and any other special cases you need, including anything where more than one person encloses an item at startup.]

Understand "my" as a thing when the player owns the item described.

After reading a command when the player is not yourself:
   if the player's command includes "my", replace the matched text with "[the printed name of the player in lower case][']s".