Merge branch 'multiparty_synchronous' into 'master'

actris/logrel/examples/compute_service.v

actris/logrel/examples/mapper.v

actris/logrel/examples/mapper_list.v

actris/logrel/examples/pair.v

actris/logrel/examples/par_recv.v

actris/logrel/examples/rec_subtyping.v

actris/logrel/lib/list.v

actris/logrel/lib/mutex.v

actris/logrel/lib/par_start.v

actris/logrel/model.v

actris/logrel/napp.v

actris/logrel/operators.v

actris/logrel/session_types.v

actris/logrel/session_typing_rules.v

actris/logrel/subtyping.v

actris/logrel/subtyping_rules.v

actris/logrel/telescopes.v

actris/logrel/term_types.v

actris/logrel/term_typing_judgment.v

actris/logrel/term_typing_rules.v