bash-2.05a$ mwrank3 Program mwrank: uses 2-descent (via 2-isogeny if possible) to determine the rank of an elliptic curve E over Q, and list a set of points which generate E(Q) modulo 2E(Q). and finally search for further points on the curve. For more details see the file mwrank.doc. For details of algorithms see the author's book. Please acknowledge use of this program in published work, and send problems to John.Cremona@nottingham.ac.uk. Version compiled on Feb 11 2003 at 17:40:15 by GCC 3.2.1 using base arithmetic option LiDIA_ALL (LiDIA bigints and multiprecision floating point) Using LiDIA multiprecision floating point with 15 decimal places. Enter curve: [0,0,0,-144,1296] Curve [0,0,0,-144,1296] : Working with minimal curve [0,0,1,-9,20] [u,r,s,t] = [2,0,0,4] No points of order 2 Basic pair: I=432, J=-34992 disc=-901953792 2-adic index bound = 2 By Lemma 5.1(a), 2-adic index = 1 2-adic index = 1 One (I,J) pair Looking for quartics with I = 432, J = -34992 Looking for Type 3 quartics: Trying positive a from 1 up to 9 (square a first...) (1,0,-72,324,-396) --nontrivial...(x:y:z) = (1 : 1 : 0) Point = [12 : 40 : 1] height = 1.48635271333215 Rank of B=im(eps) increases to 1 (1,0,-60,244,-264) --trivial (1,0,-6,28,33) --trivial (1,0,0,36,36) --nontrivial...(x:y:z) = (1 : 1 : 0) Point = [0 : 4 : 1] height = 0.340523652529288 Rank of B=im(eps) increases to 2 (1,0,12,44,24) --trivial (9,-12,0,12,0) --trivial Trying positive a from 1 up to 9 (...then non-square a) (2,-2,18,18,0) --trivial (6,-2,-18,18,0) --trivial Trying negative a from -1 down to -3 Finished looking for Type 3 quartics. Mordell rank contribution from B=im(eps) = 2 Selmer rank contribution from B=im(eps) = 2 Sha rank contribution from B=im(eps) = 0 Mordell rank contribution from A=ker(eps) = 0 Selmer rank contribution from A=ker(eps) = 0 Sha rank contribution from A=ker(eps) = 0 Rank = 2 Points generating E(Q)/2E(Q): Point [0 : 36 : 1], height = 0.340523652529288 Point [48 : 324 : 1], height = 1.48635271333215 After descent, rank of points found is 2 Transferring points back to original curve [0,0,0,-144,1296] Generator 1 is [0 : 36 : 1]; height 0.340523652529288 Generator 2 is [48 : 324 : 1]; height 1.48635271333215 The rank has been determined unconditionally. The basis given is for a subgroup of full rank of the Mordell-Weil group (modulo torsion), possibly of index greater than 1. Regulator (of this subgroup) = 0.133113726866795 (4.6 seconds) Enter curve: [0,0,0,0,0] bash-2.05a$