* `[[n,equals4],[Variable1,Variable2]]` e.g. `[[n,equals4],[[[v,c],"|",[v,d]],[1,2,3]]]` returns `[v,c]=1` and `[v,d]=[2,3]`.  You may use either order (i.e. a=1 or 1=a).  Multiple items are allowed in the head of the list, there may be lists within lists, and lists with pipes must have the same number of items in the head in each list, or no pipe in the other list.

* `[[n,findall],[Variable1,Variable2,Variable3]]` e.g. `[[[n,equals3],[[v,a],[1,2,3]]],[[n,findall],[[v,a1],[[n,member],[[v,a1],[v,a]]],[v,b]]]]` returns `[v,b]=[1,2,3]`

* `[[n,string_from_file],[Variable1,Variable2]]` e.g. `[[n,string_from_file],[[v,a],"file.txt"]]` returns `[v,a]="Hello World"`

* `[[n,maplist],[Variable1,Variable2,Variable3,Variable4]]` e.g. `[[n,maplist],[[n,+],[1,2,3],0,[v,b]]]` returns `[v,b]=6`

* `[[n,string_length],[Variable1,Variable2]]` e.g. `[[n,string_length],["abc",[v,b]]]` returns `[v,b]=3`

* `[[n,sort],[Variable1,Variable2]]` e.g. `[[n,sort],[[1,3,2],[v,b]]]` returns `[v,b]=[1,2,3]`

* `[[n,intersection],[Variable1,Variable2]]` e.g. `[[n,intersection],[[1,3,2],[3,4,5],[v,b]]]` returns `[v,b]=[3]`

* `[[n,read_string],[Variable1]]` e.g. `[[n,read_string],[[v,a]]]` asks for input and returns `[v,a]="hello"`