I just realized (painfully close to my deadline) that my essay on self-referential sentences could really benefit from a terminological distinction that I may have to coin. It's the distinction between Deduction style #1: If P says "Q is true", and P is true, then Q is true. and Deduction style #2: If P says "Q is true", and Q is true, then P is true. I'm tempted to call them "pushing" and "popping", respectively. And now that I think about it, I'm wondering whether Hofstadter used exactly this nomenclature in "Godel, Escher, Bach". I can't decide whether it's merely the sort of thing Hofstadter would do, or something he actually did! And I can't seem to locate my copy of GEB. Can someone with a handy copy look up "push" and "pop" in the index? Thanks, Jim Propp