On Mon, Sep 1, 2008 at 11:42 AM, Mov GP 0 wrote: > I'm new to axiom and tried to count the elements in a cyclic > list and expected to get %PositiveInfiniy as Answer. Instead it > resulted in an infinite loop. Version is Axiom 3.9 (September 2005) >
Welcome. You are using a rather old version of Axiom. Perhaps you should upgrade to one of the newer version in the axiom family: Axiom: http://www.axiom-developer.org/ OpenAxiom: http://www.open-axiom.org/ FriCAS: http://fricas.sourceforge.net/ > ======================================= > What I've did: > > u:= [9,2,4,7]; concat! (u, [1,2,42]); end := rest(u,4); part := > rest(u,2); setrest!(end, part); > > u is now [9,2,(42,7,1)] -- the () are the cyclic part > > when you count the elements using "#u" then it resolves in a loop. > I can confirm that this works in FriCAS: FriCAS (AXIOM fork) Computer Algebra System Version: FriCAS 2008-02-09 Timestamp: Thursday March 27, 2008 at 18:27:30 ----------------------------------------------------------------------------- Issue )copyright to view copyright notices. Issue )summary for a summary of useful system commands. Issue )quit to leave FriCAS and return to shell. ----------------------------------------------------------------------------- (1) -> u:= [9,2,4,7]; concat! (u, [1,2,42]); end := rest(u,4); part :=rest(u,2); setrest!(end, part); Type: List PositiveInteger (2) -> u _____ (2) [9,2,4,7,1] Type: List PositiveInteger (3) -> #u >> System error: LENGTH: A proper list must not be circular: #1=(9 2 . #2=(4 7 1 . #2#)) > ======================================= > What I 've expected: > > There should be a Property like "isCyclic?" that tests if the list > is cyclic. There is an operator. Browse the List constructor in hyperdoc. Look for 'cyclic?'. (3) -> cyclic? u (3) true Type: Boolean > The new code for counting should be something like > > count(x) == if isCyclic? x then return ?PositiveInfinity else #x > (4) -> count(x) == if cyclic? x then return %PositiveInfinity else #x Type: Void ( 5) -> count u Compiling function count with type List PositiveInteger -> Polynomial Integer (5) %PositiveInfinity Type: Polynomial Integer > ======================================= > Question: > Is this fixed already in a newer version? > If this doesn't work in other forks of Axiom then it should be reported as an error. Regards, Bill Page. _______________________________________________ Axiom-developer mailing list Axiom-developer@nongnu.org http://lists.nongnu.org/mailman/listinfo/axiom-developer
