There are a few other miscellaneous higher-order tasks that are useful for running other code in controlled ways.  You may want to skip over this unless you want to do a lot of Step programming.

Begin

[Begin code ...]

Like Call, but allows you to specify several calls in a row.  It runs them as if they'd been typed in the code directly.

Once

[Once ?call]

Runs ?call but stops after the first successful path.  If the program backtracks, it won't search for another solution to ?call.  This is useful if you only care about one solution but ?call might potentially have many (or infinite) solutions that could bog the program down.

IgnoreOutput

[IgnoreOutput ?call]

Runs ?call but throws away any output it generates.