formulas(hints). % 72 hints from 3 proof(s) in file easy.out, Fri Apr 13 08:53:42 2007 f(f(x,x),f(x,x)) = x # label(Sheffer_1) # label(goal) # label(1). f(f(x,y),f(x,f(y,z))) = x # label(2). f(x,f(y,f(x',z))) = f(x,y') # label(3). x' = f(x,x) # label(4). f(x,x) = x' # label(5). f(f(c1,c1),f(c1,c1)) != c1 # label(Sheffer_1) # answer(Sheffer_1) # label(6). c1'' != c1 # answer(Sheffer_1) # label(7). f(f(x,y),f(x,y')) = x # label(8). f(x',f(x,x')) = x # label(9). f(x,f(y,x)) = f(x,y') # label(10). x'' = x # label(11). $F # answer(Sheffer_1) # label(12). f(x,f(y,f(y,y))) = f(x,x) # label(Sheffer_2) # label(goal) # label(13). f(x,y) = f(y,x) # label(14). f(c2,f(c3,f(c3,c3))) != f(c2,c2) # label(Sheffer_2) # answer(Sheffer_2) # label(15). f(c2,f(c3,c3')) != c2' # answer(Sheffer_2) # label(16). f(f(x,y),f(y,f(x,z))) = y # label(17). f(f(x,y),f(x,f(z,y))) = x # label(18). f(x',f(x,y)) = x # label(19). f(x',f(y,x)) = x # label(20). f(x,f(x,y)') = f(x,y) # label(21). f(x,f(y,x)') = f(y,x) # label(22). f(x,f(x,y)) = f(x,y') # label(23). f(f(x,y),f(x,y)') = f(x',f(x,y)') # label(24). f(x',f(y,x)') = f(y',f(y,x)') # label(25). f(x',f(x,y)') = f(x,x') # label(26). f(x',f(y,x)') = f(x,x') # label(27). f(x,x') = f(y,y') # label(28). f(x,f(y,y')) = x' # label(29). f(f(f(x,x),y),f(f(z,z),y)) = f(f(y,f(x,z)),f(y,f(x,z))) # label(Sheffer_3) # label(goal) # label(30). f(f(f(c4,c4),c5),f(f(c6,c6),c5)) != f(f(c5,f(c4,c6)),f(c5,f(c4,c6))) # label(Sheffer_3) # answer(Sheffer_3) # label(31). f(f(c5,c4'),f(c5,c6')) != f(c5,f(c4,c6))' # answer(Sheffer_3) # label(32). f(f(x,y),f(f(y,z),x)) = x # label(33). f(x,f(f(x,y),f(f(x,f(y,z)),u))) = f(x,y) # label(34). f(x,f(y,f(z,x'))) = f(x,y') # label(35). f(x,f(f(x',y),z)) = f(x,z') # label(36). f(x,f(x',y)') = f(x,x') # label(37). f(f(x,y),f(f(x,z),y)) = y # label(38). f(f(x,y),f(y,x')) = y # label(39). f(f(f(x,y),z),f(z,y)) = z # label(40). f(x',f(y,f(x,z))) = f(x',y') # label(41). f(f(x,y),f(f(z,y),x)) = x # label(42). f(x,f(f(x,y),f(y,z))) = f(x,y) # label(43). f(x,f(f(x,f(y,z)),f(f(x,z),u))) = f(x,f(y,z)) # label(44). f(f(x,f(y,z)),f(z,x)) = x # label(45). f(f(x,y),f(f(y,x'),f(y,z))) = f(y,x') # label(46). f(f(x,y'),f(x,f(f(x,y),z))) = x # label(47). f(f(x,y'),f(x,f(z,f(x,y)))) = x # label(48). f(x',f(f(x,y),z)) = f(x',z') # label(49). f(f(x,y)',f(f(x,z),y)) = f(y,f(x,z)') # label(50). f(x,f(f(y,x'),z)') = f(x,z) # label(51). f(f(f(x,y),z),f(z,y)') = f(z,f(x,y)') # label(52). f(f(x,f(y,z')),f(f(y,z),x)) = x # label(53). f(x,f(f(x',y)',z)) = x' # label(54). f(x',f(f(x,y)',z)) = x # label(55). f(x',f(f(y,x)',z)) = x # label(56). f(x',f(y,f(z,x)')) = x # label(57). f(x,f(y,f(z,x)')') = f(y,f(z,x)') # label(58). f(f(x,y),f(y,z)') = f(x',f(y,z)') # label(59). f(f(x,y)',f(z,y)') = f(z,f(x,y)') # label(60). f(f(x,y)',f(z,y)) = f(f(x,y)',z') # label(61). f(f(x,y)',f(x,z)') = f(f(x,y)',z) # label(62). f(f(x,y)',z) = f(y,f(x,z)') # label(63). f(x,f(y,z)') = f(y,f(x,z)') # label(64). f(x',f(f(y,x),z)') = f(x',z) # label(65). f(f(x,y),f(z,f(x,y'))') = f(z,x') # label(66). f(x,f(y,f(x,z)')) = f(x,f(y,z)) # label(67). f(x,f(f(x,y),z)) = f(x,f(y',z)) # label(68). f(x,f(y,f(z,f(f(x,y),u))')) = f(x,f(z,y)) # label(69). f(x,f(y,f(x,z))) = f(x,f(y,z')) # label(70). f(f(x,y'),f(x,f(y,z))) = f(x,f(y,z))' # label(71). f(f(x,y'),f(x,z)) = f(x,f(y,z'))' # label(72). end_of_list.