Introspectors
You can inspect the language itself using inspectors called introspectors.
Here are some example queries to try:
properties whose (it as string contains "file")
properties whose (result type of it = type "file")
properties of type "file"
casts
unary operators
binary operators
binary operators returning (type "integer")
properties
If you evalaute the last one, 'properties', most of the items at the top of the list are the core types and introspectors.