A Mechanically Proved and an Incremental Development of the Session Initiation Protocol INVITE Transaction

Box 3

INVARIANTS

inv1: cl_sent REQUESTS

inv2: sr_got REQUESTS

inv3: sr_sent RESPONSES

inv4: cl_got RESPONSES

inv5:     REQUESTS   m   cl_sent ⇒ m   sr_got

inv6:    2208 RESPONSES   l   sr_sent ⇒  l   cl_got