Expression Elements
Several single properties used in schemas and filters can be combined into a mathematical expression and calculated accordingly.
Expressions passed to other expressions must be enclosed in curly braces.
For example the expression income&/1000 when passed to CalcItems would be:
CalcItems("Addresses",{income&/1000},OP_Sum,ST_Within,ST_Geometry)
A further example of this nesting of expressions is shown in the CalcItems description in the Spatial section of this topic.