Can the Element function only be used for the domains given in the documentation? I am trying to use it to determine if a value is contained in a previously defined list. Thanks!
There are as usual several ways. The most convenient one is probably
If you have a complex structure and not only a flat list, then
Finally, note that you can specify the level where
I have not tested it, but this dirty hack might be pretty fast IF you have to assess membership in a list of symbolic values with no zeros.
Adding Flatten wil take care of nested list.
(It's a dirty hack, so beware: it might bite you).