Outputs TRUE if
thing2 are the same object, so that applying a mutator to one will change the other as well.
Outputs FALSE otherwise, even if the inputs are equal in value.
WARNING: Primitives whose names start with a period are dangerous. Their use by non-experts is not recommended. The use of mutators can lead to circular data structures, infinite loops, or crashes.
MAKE "x 1 MAKE "y 1 SHOW .EQ :x :yfalse
SHOW .EQ :x :xtrue