FORMULAS
➀ | forall s, t, u (s ->* t & s ->* u => t join u) |
➁ | forall s, t, u (s ->* t & s -> u => t join u) |
➂ | forall t, u (t <->* u => t join u) |
➀ | forall s, t, u (s ->* t & s ->* u => t join u) |
➁ | forall s, t, u (s ->* t & s -> u => t join u) |
➂ | forall t, u (t <->* u => t join u) |