#logic and programming

An example of deadlock is two girls dating two men.  Girl 1 (G1) is dating Man 1 (M1). Girl 2 (G2) is dating Man 2 (M2).  Girl 1 wants to be dating Man 2, but she won't break up with Man 1 until she knows that she can successfully get Man 2.  Girl 2 want to date Man 1, but she won't break up with Man 2 until she knows that she can successfully get Man 2.  The girls are in deadlock because they both want to date Man 1 and Man 2, but both man 1 and man 2 are currently in relationships and will not cheat on their respective girlfriends.  In order for the deadlock to be solved, Girl 2 must break up with Man 2 in order to release him.  If Girl 2 breaks up with Man 2 and releases him, Girl 1 can start dating Man 2, which means she can break up with Man 1 and release him.  Because Man 1 is now free, Girl 2 can now date Man 2.