Description

Sometimes, you'll want to refer to a single set expression or transform again and again when constructing other set expressions. This command lets you assign a name to a set expression or transform; you can then use the name in other expressions instead of writing out the whole transform or set expression over again.

BBQ uses the same name space for both set expressions and transforms; you can re-use a given name to give it a different meaning, but the name will only refer to either a set expression or a transform at any one time. Also, changing the meaning of a name does not change the meaning of any existing definitions that might have been made using the old definition of the name.