Sharvy's Lucy and Benjamin Puzzle

Thomas Forster
2008 Studia Logica: An International Journal for Symbolic Logic  
Sharvy's puzzle concerns a situation in which common knowledge of two parties is obtained by repeated observation each of the other, no fixed point being reached in finite time. Can a fixed point be reached?
doi:10.1007/s11225-008-9153-2 fatcat:2hnlc7isizdqrn6buihxdknosu