#lang syndicate/test (spawn (on (message "ping") (printf "ping\n") (send! "pong"))) (spawn (on (message "pong") (printf "pong\n") (send! "ping")) (on-start (send! "ping"))) (trace (message "ping") (message "pong") (message "ping") (message "pong") (message "ping") (message "pong") (message "ping") (message "pong"))