I have installed a package named HEP from Wolfram Library Archive which contains several .m files by Files -> Install (Install for this user only) and by loading it in a notebook by <<Package`.

One of the them is Spinor.m which when loaded gives the following error message saying Cannot set DownValues to ValueList

Problem loading Spinor.m package

I have not encountered such a problem of this kind before and couldn't find any documentation regarding this issue.

Another problem occurs while loading the StandardModel.m package in a similar way resulting the error message

TagSet and TagSetDelayed error

I would request to download the Spinor.m package from the Wolfram Library Archive and try it out in your own Mathematica as I am not sure whether the problem is with my machine (using Mathematica 11.0) or not. Any solution or guidance regarding the first problem is highly encouraged to resolve this problem. THANKS for all valuable suggestions in advance !


1 Answer 1


That is an ancient package (revision date 1991-07-01) and it is unsurprising there are incompatibilities. Specifically the package seems to be making definitions in a strange way with an undocumented function ValueList in e.g.

If[$VersionNumber > 1.9, DownValues[AbsSquared1] = ValueList @@ AbsSquared1Rules, 
 DownValue[AbsSquared1] = ValueList @@ AbsSquared1Rules]

As a first attempt at fixing this you might try loading the package with:

Block[{System`ValueList = List},

However I expect you will run into other problems while attempting to make this package work.

  • $\begingroup$ The error message is suppressed but the problem remains whenever anything related to Spinor.m is encountered. @Mr.Wizard $\endgroup$
    – Rohan
    Commented Jul 21, 2018 at 7:25
  • 1
    $\begingroup$ @Rohan As I said I am not surprised; the package may require a complete rewrite for contemporary versions of Mathematica. Among many other things NonCommutativeMultiply is now a built-in function and not necessarily compatible with the package Symbol of the same name; you may need context manipulation to get around this. Honestly if you can find an alternative to using this package I recommend you do so, as it may be a lot of work for you otherwise. $\endgroup$
    – Mr.Wizard
    Commented Jul 21, 2018 at 7:33
  • $\begingroup$ Thanks for the Advice @Mr.Wizard. In addition, can you name any such packages for Mathematica other than FeynArts or FeynCalc for High Energy Physics for calculating Cross Sections and other relevant details? $\endgroup$
    – Rohan
    Commented Jul 21, 2018 at 7:36
  • $\begingroup$ @Rohan Unfortunately I cannot; that topic is well outside my realm of knowledge. $\endgroup$
    – Mr.Wizard
    Commented Jul 21, 2018 at 7:37
  • $\begingroup$ @Rohan As far as diagram generators are concerned, there are no other Mathematica packages than FeynArts. Many people also use QGRAF, but this Fortran code lacks a GUI or even a diagram plotter and is more difficult to use than FeynArts. As for FeynCalc-like packages, have a look at HEPMath (hepmath.hepforge.org) and Package-X (packagex.hepforge.org). AFAIK HEPMath is not actively developed anymore, but the last release was not so long time ago, so it should still work with the recent Mathematica versions. Package-X is still actively developed, but it has no interface to FeynArts. $\endgroup$
    – vsht
    Commented Jul 23, 2018 at 7:37

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