signature { automatic } theory { n1:(p1 --> <>([](<>p1 <--> []<>(p1 v false)))); n2:(([](<>p1 <--> []<>(p1 v false))) -> [](([](p1 <--> (n2:n1 v []<>p2))))); n1:!n2; n3:<>n1; n3:<>n2; n1:<>n2; n2:<>n1; n1:!(([](p1 <--> (n2:n1 v []<>p2)))); n3:<>(n2 & ([](<>p1 <--> []<>(p1 v false)))) }