Here - Agents Lab - University of Nottingham

* error: wrong type for the param value speed */startCooling (speed: "fast") on condThe target of an operation (e.g., on cond) can be omitted (as it happens in somepoints in plans of ACMEThermostat shown in Fig. 3) when there is no ambiguitywith respect to the target of the artifacts that are currently used by the agent(specified in the using: attribute).On the event/percept side, we can check beliefs representing artifact observableproperties in the event template of rules and in any expression appearingeither in the context or in action rule body, containing such beliefs.For what concerns event templates, given an action rule: updated Prop inTarget : Context => Action , where the event concerns the update of thebelief about an observable property P rop in the artifact of type I denoted byT arget, then the following checks apply:– there must exist an observable property defined in I which matches P rop;– the action rule must appear in an action rule block (or in any of its parentblock) where T arget has been explicitly listed among the artifacts used bythe agent through the using: attribute.As in the case of operations, in Target can be omitted if there is no ambiguityabout the artifact which is referred and its type.Examples of checks follow, supposing to have a fragment of a script withbeliefs cond: Conditioner and therm: Thermometer about a conditioner andthermometer artifact:/* compilation ok */updated currentTemp => println(msg: "the temperature has changed")updated currentTemp : isHeating=> println(msg: "the temperature has changed while heating...")sum: double = currentTemp in therm + 1/* error: unknown obs property isHeating in Thermometer type */updated isHeating in therm => .../* error: wrong type */bak: boolean = currentTemp in thermOn the environment side the definition of the interface as a type allows forchecking the conformance of artifact templates that declare to implement thatinterface, so that:– for each operation signature Op declared in any of the interfaces I implementedby the template, the template must contain the implementation ofthe operation;– for any observable property P rop that appears in expressions or assignmentsin operation implementation, then the declaration of the observable propertymust appear in one of the interfaces implemented by the template and thecorresponding type expression must be compatible.144