DLV [build BEN/Oct 11 2007   gcc 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)]

true is bravely true, evidenced by {next(1,2), next(2,3), next(3,4), next(4,5), next(4,21), next(5,6), next(6,7), next(7,8), next(7,19), next(8,9), next(8,12), next(9,10), next(10,11), next(12,13), next(12,16), next(13,14), next(14,15), next(16,17), next(17,18), next(19,20), next(21,22), next(22,23), next(23,24), next(23,49), next(24,25), next(25,26), next(26,27), next(27,28), next(28,29), next(29,30), next(30,31), next(31,32), next(32,33), next(33,34), next(34,35), next(35,36), next(35,47), next(36,37), next(36,40), next(37,38), next(38,39), next(40,41), next(40,44), next(41,42), next(42,43), next(44,45), next(45,46), next(47,48), next(49,50), next(50,51), next(51,52), next(52,53), next(53,54), next(54,55), next(55,56), next(56,57), next(57,58), next(58,59), next(59,60), next(60,61), next(60,72), next(61,62), next(61,65), next(62,63), next(63,64), next(65,66), next(65,69), next(66,67), next(67,68), next(69,70), next(70,71), next(72,73), doAt(startflow,3), doAt(a9,4), doAt(a7,5), doAt(a23,6), doAt(a2,7), doAt(a2,35), doAt(a2,60), doAt(a4,8), doAt(a4,36), doAt(a4,61), doAt(a1,9), doAt(a1,37), doAt(a1,62), doAt(endflow,10), doAt(endflow,14), doAt(endflow,17), doAt(endflow,19), doAt(endflow,38), doAt(endflow,42), doAt(endflow,45), doAt(endflow,47), doAt(endflow,63), doAt(endflow,67), doAt(endflow,70), doAt(endflow,72), doAt(a3,12), doAt(a3,40), doAt(a3,65), doAt(a20,13), doAt(a20,41), doAt(a20,66), doAt(a15,16), doAt(a15,44), doAt(a15,69), doAt(a6,21), doAt(a19,22), doAt(a10,23), doAt(a8,24), doAt(a16,25), doAt(a16,50), doAt(a22,26), doAt(a22,51), doAt(a18,27), doAt(a18,52), doAt(a25,28), doAt(a25,53), doAt(a5,29), doAt(a5,54), doAt(a17,30), doAt(a17,55), doAt(a12,31), doAt(a12,56), doAt(a21,32), doAt(a21,57), doAt(a14,33), doAt(a14,58), doAt(a13,34), doAt(a13,59), doAt(a24,49), ineffset(startflow,x1), ineffset(startflow,x2), ineffset(startflow,x3), ineffset(startflow,x4), ineffset(startflow,x5), ineffset(startflow,x6), ineffset(startflow,x7), ineffset(startflow,x8), ineffset(startflow,x9), ineffset(startflow,x10), ineffset(startflow,x11), ineffset(startflow,x12), ineffset(startflow,x13), ineffset(startflow,x14), ineffset(startflow,x15), ineffset(startflow,x16), ineffset(startflow,x17), ineffset(startflow,x18), ineffset(startflow,x19), ineffset(startflow,x20), ineffset(startflow,x21), ineffset(startflow,x22), ineffset(startflow,x23), ineffset(startflow,x24), ineffset(startflow,x25), ineffset(a9,co18), ineffset(a9,co19), ineffset(a7,x1), ineffset(a23,x4), ineffset(a23,x11), ineffset(a2,co4), ineffset(a2,co5), ineffset(a4,co8), ineffset(a4,co9), ineffset(a1,x6), ineffset(a1,x23), ineffset(endflow,x2), ineffset(endflow,x14), ineffset(endflow,x15), ineffset(endflow,x21), ineffset(endflow,finished), ineffset(a3,co6), ineffset(a3,co7), ineffset(a20,x6), ineffset(a20,x24), ineffset(a15,x9), ineffset(a6,x3), ineffset(a6,x17), ineffset(a6,x19), ineffset(a6,x23), ineffset(a19,x23), ineffset(a10,co20), ineffset(a10,co21), ineffset(a8,x7), ineffset(a16,x11), ineffset(a16,x14), ineffset(a16,x17), ineffset(a16,x25), ineffset(a22,x2), ineffset(a22,x7), ineffset(a22,x8), ineffset(a22,x14), ineffset(a18,x4), ineffset(a25,x20), ineffset(a5,x6), ineffset(a5,x10), ineffset(a5,x12), ineffset(a17,x1), ineffset(a17,x4), ineffset(a17,x6), ineffset(a12,x14), ineffset(a12,x22), ineffset(a12,x23), ineffset(a21,x8), ineffset(a14,x1), ineffset(a14,x24), ineffset(a13,x8), ineffset(a13,x9), ineffset(a13,x12), ineffset(a24,x10), ineffset(a24,x12), inreadset(a9,x6), inreadset(a9,x16), inreadset(a7,x14), inreadset(a23,x8), inreadset(a2,x9), inreadset(a2,x11), inreadset(a2,x17), inreadset(a4,x6), inreadset(a1,x9), inreadset(a1,x18), inreadset(endflow,x1), inreadset(endflow,x2), inreadset(endflow,x3), inreadset(endflow,x4), inreadset(endflow,x5), inreadset(endflow,x6), inreadset(endflow,x7), inreadset(endflow,x8), inreadset(endflow,x9), inreadset(endflow,x10), inreadset(endflow,x11), inreadset(endflow,x12), inreadset(endflow,x13), inreadset(endflow,x14), inreadset(endflow,x15), inreadset(endflow,x16), inreadset(endflow,x17), inreadset(endflow,x18), inreadset(endflow,x19), inreadset(endflow,x20), inreadset(endflow,x21), inreadset(endflow,x22), inreadset(endflow,x23), inreadset(endflow,x24), inreadset(endflow,x25), inreadset(a3,x24), inreadset(a20,x6), inreadset(a20,x7), inreadset(a15,x5), inreadset(a6,x3), inreadset(a19,x2), inreadset(a10,x20), inreadset(a8,x2), inreadset(a8,x18), inreadset(a8,x21), inreadset(a16,x5), inreadset(a22,x17), inreadset(a18,x14), inreadset(a25,x3), inreadset(a25,x25), inreadset(a5,x14), inreadset(a5,x15), inreadset(a5,x17), inreadset(a17,x11), inreadset(a12,x6), inreadset(a21,x12), inreadset(a14,x6), inreadset(a14,x8), inreadset(a14,x13), inreadset(a13,x9), inreadset(a24,x6), inreadset(a24,x23), activity(startflow), activity(a9), activity(a7), activity(a23), activity(a2), activity(a4), activity(a1), activity(endflow), activity(a3), activity(a20), activity(a15), activity(a6), activity(a19), activity(a10), activity(a8), activity(a16), activity(a22), activity(a18), activity(a25), activity(a5), activity(a17), activity(a12), activity(a21), activity(a14), activity(a13), activity(a24), effectsObserved(startflow,1), effectsObserved(a9,2), do(startflow,1), do(a9,2), nextvis(1,2), do(a7,5), do(a23,6), do(a2,7), impossible(a,35), impossible(a,60), do(a4,8), impossible(a,36), impossible(a,61), do(a1,9), impossible(a,37), impossible(a,62), do(endflow,10), do(endflow,14), do(endflow,17), do(endflow,19), impossible(a,38), impossible(a,42), impossible(a,45), impossible(a,47), impossible(a,63), impossible(a,67), impossible(a,70), impossible(a,72), do(a3,12), impossible(a,40), impossible(a,65), do(a20,13), impossible(a,41), impossible(a,66), do(a15,16), impossible(a,44), impossible(a,69), impossible(a,21), impossible(a,22), impossible(a,23), impossible(a,24), impossible(a,25), impossible(a,50), impossible(a,26), impossible(a,51), impossible(a,27), impossible(a,52), impossible(a,28), impossible(a,53), impossible(a,29), impossible(a,54), impossible(a,30), impossible(a,55), impossible(a,31), impossible(a,56), impossible(a,32), impossible(a,57), impossible(a,33), impossible(a,58), impossible(a,34), impossible(a,59), impossible(a,49), impossible(a,48), impossible(a,73), impossible(a,39), impossible(a,64), impossible(a,43), impossible(a,46), impossible(a,68), impossible(a,71), nextvis(5,6), nextvis(6,7), nextvis(7,8), nextvis(7,19), nextvis(8,9), nextvis(8,12), nextvis(9,10), nextvis(12,13), nextvis(12,16), nextvis(13,14), nextvis(16,17), nextvis(2,5), nextvis(10,11), nextvis(14,15), nextvis(17,18), nextvis(19,20)}