This paper proposes the removal of system_executor and system_context from the Networking TS.
The Networking TS  provides two related classes: system_executor and system_context.
system_executor satisfies the named requirements DefaultConstructible and Executor. system_context satisfies the named requirement ExecutionContext.
The type alias system_context::executor_type names system_executor. The member function system_context::get_executor returns a default constructed system_executor. The member function system_executor::context returns a reference to a system_executor with static storage duration. Note that system_executor::context need not return a system_context which is a “Meyer’s singleton” .
The only direct use of system_context in the Networking TS is in the specification of system_executor.
system_executor is directly used by the Networking TS in the specification of associated_executor and associated_executor_t where it is used as a “fallback” executor. This means that the unary versions of dispatch, defer, and post may make use of this type.
During review of the design of the asynchronous model of the Networking TS  concerns were raised about the implication and usage of system_context::stop and system_context::join. This review and those concerns were discussed in SG4 in Prague 2020.