bash-2.05$ ./rankdist/mwrank -b 17 -c 17 -p 150 NB: reducing hlimc to 15 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 Apr 17 2002 at 20:36:44 by GCC egcs-2.91.66 19990314 (egcs-1.1.2 release) using base arithmetic option LiDIA (LiDIA bigints and multiprecision floating point) Using LiDIA multiprecision floating point with 150 decimal places. Enter curve: [0,0,0,877,0] Curve [0,0,0,877,0] : 1 points of order 2: [0 : 0 : 1] Using 2-isogenous curve [0,0,0,-3508,0] ------------------------------------------------------- First step, determining Selmer group ------------------------------------------------------- ------------------------------------------------------- Rank <= 1 ------------------------------------------------------- Second step, determining E(Q)/phi(E'(Q)) and E'(Q)/phi'(E(Q)) ------------------------------------------------------- 1. E(Q)/phi(E'(Q)) ------------------------------------------------------- This component of the rank is 0 ------------------------------------------------------- 2. E'(Q)/phi'(E(Q)) ------------------------------------------------------- First stage (no second descent yet)... (-1,0,0,0,3508): no rational point found (hlim=6) (877,0,0,0,-4): no rational point found (hlim=6) After first descent, this component of the rank has lower bound 0 and upper bound 1 (difference = 1) Second descent will attempt to reduce this Second stage (using second descent)... d1=-1: (x:y:z) = (17094272394:1225552166375894736202:4612160965) Curve E' Point [-1347738689963849825320053802740 : -20949922565086352416107761007588 : 98110020725836091788986632125], height = 47.9901859939819919864248467537725769880513544530798873319498957455980434609748453303446486044509514137896814333340916824954434693012650342316143197946 Curve E Point [29604565304828237474403861024284371796799791624792913256602210 : -256256267988926809388776834045513089648669153204356603464786949 : 490078023219787588959802933995928925096061616470779979261000], height = 95.9803719879639839728496935075451539761027089061597746638997914911960869219496906606892972089019028275793628666681833649908869386025300684632286395891 Second descent successfully found rational point for d1=-1 ------------------------------------------------------- Summary of results: ------------------------------------------------------- rank(E) = 1 #E(Q)/2E(Q) = 4 Information on III(E/Q): #III(E/Q)[phi'] = 1 #III(E/Q)[2] = 1 Information on III(E'/Q): #phi'(III(E/Q)[2]) = 1 #III(E'/Q)[phi] = 1 #III(E'/Q)[2] = 1 ------------------------------------------------------- List of points on E = [0,0,0,877,0]: I. Points on E mod phi(E') --none (modulo 2-torsion). II. Points on phi(E') mod 2E Point [29604565304828237474403861024284371796799791624792913256602210 : -256256267988926809388776834045513089648669153204356603464786949 : 490078023219787588959802933995928925096061616470779979261000], height = 95.9803719879639839728496935075451539761027089061597746638997914911960869219496906606892972089019028275793628666681833649908869386025300684632286395891 ------------------------------------------------------- Computing full set of 2 coset representatives for 2E(Q) in E(Q) (modulo torsion), and sorting into height order....done. Rank = 1 Height Constant = 7.86708066408703654559531059931032359600067138671875 Max height = 95.9803719879639839728496935075451539761027089061597746638997914911960869219496906606892972089019028275793628666681833649908869386025300684632286395891 Bound on naive height of extra generators = 18.5315664405274792092452765445931184822343057096253916293221990545773429913277434067432552454335447586199292074075759294434318820669477853848031821766 Only searching up to height 17 After point search, rank of points found is 1 Generator 1 is [29604565304828237474403861024284371796799791624792913256602210 : -256256267988926809388776834045513089648669153204356603464786949 : 490078023219787588959802933995928925096061616470779979261000]; height 95.9803719879639839728496935075451539761027089061597746638997914911960869219496906606892972089019028275793628666681833649908869386025300684632286395891 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) = 95.9803719879639839728496935075451539761027089061597746638997914911960869219496906606892972089019028275793628666681833649908869386025300684632286395891 (442.41 seconds) Enter curve: [0,0,0,0,0] bash-2.05$