Hi Kurt, Thanks for tracking. I am sorry that I have not been doing such a good job of pushing changes to github. The specific problems that you see are the result of some experimentation. Things are still in a state of fairly rapid evolution and I should have something new later today, time permitting. As you noticed I have been experimenting with different term orderings as I try to enrich the set of rewrite rules. As might be expected I have found a few cases that result in non-termination and have been looking for inspiration in the literature. For example:
https://www.researchgate.net/publication/223818521_Termination_and_completion_modulo_associativity_commutativity_and_identity http://www.cs.tau.ac.il/~nachum/papers/survey-draft.pdf and several others by Jean-Pierre Jouannaud https://www.researchgate.net/profile/Jean-Pierre_Jouannaud/timeline Of course there are many other and newer papers on this subject but I have yet to find one that is a good match for what I am trying to do right now. If you have any suggestions that would be great. Bill. On 9 February 2017 at 21:13, Kurt Pagani <[email protected]> wrote: > Bill, > > I pulled the latest version of sexpr.spad today and now get an error I have no > explanation for (I created a unit test file using the input from the sandbox). > > Four of the seven errors (see tail of sexpr.output) are not errors as such, > only > caused by the ordering. > > case ex2:20 and 21 might be caused by the Unittest itself, though I'm not > sure. > > case ex4:4 is strange: the rule application "rc t2" does not work anymore and > building "expr" take 30s, and even worse "rc rs expr" takes almost 100s > (result > is wrong due to failing of "rc"). > > I had a look at the diff on github but got no clue where it might come from. > You will certainly find it in no time. > Kurt > > > Am 05.02.2017 um 05:05 schrieb Bill Page: >> The reason that i wrote this as _rule is because the interpreter seems >> to have a bug that coerces things to Expression Integer. Using the >> function call syntax seems to get around that and I also use a package >> call in order to be very specific if necessary. > > -- > You received this message because you are subscribed to the Google Groups > "FriCAS - computer algebra system" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/fricas-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
