# Constraints

Constraint Composition:

Constraints are composed using member and local variables in expressions separated by operands such as:

 • /
 • *
 • %
 • +
 • -
 • >
 • >=
 • <
 • <=
 • OR
 • AND
 • (
 • )

The following is an example Conditional expression that returns a Boolean True/False:

( (x%2) > 1) AND (y >= 10) )

Variables can be scoped by either  '.' or '->'

c.Name  :  c.Names[0] of an array as  c.Names[0].Surname= "Smith"

There are two types of operators you can use on constraints:

 • Logical operators AND and OR can be used to combine constraints
 • Equivalence operators '=' and '!=' can be used to define the conditions of a constraint

All constraints are subject to an AND operation unless otherwise specified; you can use the OR operation on them instead, for example:

Location=0 OR

Location=1 AND

Departing.Name!=Central

(a AND b)

(a.b AND ( b.a OR c.a))

Below are some examples of using the equivalence operators:

m_value!="true"

m_value <> 0

m_value[10]="john"

m_value[0][1]=2

Notes

 • Quotes around strings are optional; the comparison for strings is always case-sensitive in determining the truth of a constraint