builtins(internal = FALSE).Internal) should
be returned.builtins() returns an unsorted list of the objects in the
symbol table, that is all the objects in the base environment.
These are the built-in objects plus any that have been added
subsequently when the base package was loaded. It is less confusing
to use ls(baseenv(), all = TRUE). builtins(TRUE) returns an unsorted list of the names of internal
functions, that is those which can be accessed as
.Internal(foo(args ...)) for foo in the list.