main
ruby/spec describes 7 methods in core/main, and Metorex implements 7 of them. The parameters are what Method#parameters answers under Metorex.
main#define_method: implemented, parameters[[:rest, :*]]. An example calling it.main#include: implemented, parameters[[:rest, :*]]. An example calling it.main#private: implemented, parameters[[:rest, :*]].main#public: implemented, parameters[[:rest, :*]].main.ruby2_keywords: implemented, parameters[[:rest, :*]].main#to_s: implemented, parameters[]. An example calling it.main.using: implemented, parameters[[:rest, :*]].
The method summaries are the first sentences of Ruby's own documentation for each method, read from MRI 4.0.6's ri data. Ruby's documentation is distributed under Ruby's license.