problem-set/pelletier/p40.desc created : 07/25/86 revised : 08/17/89 Natural Language Description: Full Predicate Logic (without Identity and Functions). Problem # 40. If there were an 'anti-Russell set' (a set which contains exactly those sets which are members of themselves), then not every set has a complement. (Ey)(Ax)(Fxy <-> Fxx) -> -(Ax)(Ey)(Az)(Fxy <-> -Fzx) Versions: p40.in - declarative representation. created by : From Pelletier paper, 1986. verified for ITP : untested, 07/25/86 translated for OTTER by : caw. verified for OTTER : 08/17/89.