Checking the Skeletal version

Although there is more to do, the code entered so far is enough to be able to see that:

  • we have added a new builtin, and

  • we can get information about the builtin.

So let us try this much. Fire up a a version Django interface that has access to the development version of mathics-core

$ cd Mathics3/mathics-django
$ make runserver
Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
August 21, 2022 - 01:19:05
Django version 4.0.5, using settings 'mathics_django.settings'
Starting development server at

Connect to or the address above and go into the “about” section and see that you are using right version of mathics core.

Finally click the “?” at the extreme right and type “Undef”. You should see the information that you added in the docstring:

Help for the built-in Symbol in Mathics Django

Click on the link WMA in blue and you should see the WMA documentation for this. You can also click on the preceding entry in the documentation Pi as well as the following entry Underflow and see that this works.

Inside the stripped-down command-line interface inside mathics core called mathics we can also see this builtin

$ mathics --full-form

Mathics 5.0.3dev0
on CPython 3.8.12 (heads/v2.3.4.1_release:4a6b4d3504, Jun  3 2022, 15:46:12)

In[1]:= Undefined
Out[1]= Undefined

We used the special flag --full-form which shows the expanded input. When we typed in “Undefined” note that we got the name space filled out as System. Before adding this class it would have appeared in the namespace Global.