expr.init

Use this property to give variables an initial value. Depending on their use, the variables can be state or static variables.

<service 
  name="Bartender" 
  provision="expr">
  <prop 
    name="expr.init" 
    GinsServed="0"/>
  <prop 
    name="expr.state" 
    GinsServed="NewGinsServed"/>
</service>
Tip: An expression in expr.src can also initialise a state variable. For example, NewFoo = 0. This leads to a state change, as opposed to using expr.init, with the attribute Foo="0".