• Arithmetic: can be designated by expressions (see below), numeric literals such as 50 or 21.75, or identifiers such as roughMass or machine.cycleTime.

• String: can be designated by expressions (see below), string literals, such as ‘Material Cost’, or identifiers such as op.name.

• Boolean: can be designated by expressions (see below), the boolean literals true and false, or identifiers such as op.isManualOverride.

• Object: can be designated by expressions (see below) or identifiers such as part, gcd, or machine. Each object has one or more named fields which you can access using dot notation, as in part.volume or part.material. The value of a field can be any type of CSL-supported value, including a collection or other object.

• Collection: can be designated by expressions (see below) or identifiers such as childOps or tubLaserCutting. Note that a cost model’s lookup tables are collections; each collection element is a table row, and each collection-element field corresponds to a table column. You can retrieve a collection’s elements by using query or foreach expressions.