Any expression that returns a value.
The value is what is tested by each of the rule columns. This can be a single value or a set of values.

Cell Content	description
color	A variable name
customer.name	A data element within the customer object
customers	A set of objects (of any type)
color=’red’	True if color is red, otherwise false
color=car.color	Boolean True if the two item have identical values
{p in Persons}	Returns the size of p. p is a set of persons that can be referenced in other conditions. If there are no persons then it returns 0.The rules will operate on every p in Persons whenever p is referenced in a rule

Could also be literals, but this would be unusual:

Cell Content	description
T	Boolean literal
‘large’	String literal

If no operator specified then = (comparison) is assumed is any expression that evaluates to a value (single or set)

Cell Content	description
T, F	boolean
‘red’,’green’	string
>5, [5..10], >=500	comparison with literal – yields boolean
>limit	comparison with a variable
<=cust.creditLimit	comparison with a data element of an object
>=CreditScore(SSN)	comparison with the return value of a function call (or a microservice call)

NOTE: The data type of the must be compatible (i.e. able to be compared with) the data type of the ) Ultimately after comparing the with the we MUST end up with a boolean

Can be either a data element name or an imperative statement

1. If it’s a date element name then it gets set to the value in the column
2. If it’s an imperative expression then the will be X (checkbox) if it is to be executed

• price
• cust.order
• setOfThings

Is either

1. any expression that evaluates to a value (single or set)
2. a checkbox (if checked it indicates the is to be performed.