Here - Agents Lab - University of Nottingham

1 org - model SmartHome {23 roles :4 HomeAdmin , Thermostat , ...;56 interfaces :7 Conditioner , Thermometer , Log , ...;89 workspace mainRoom {10 log : Log ;11 majordomo : HomeAdmin ;12 ...13 }1415 workspace bedroom {16 therm : Thermometer ;17 cond : Conditioner ;18 thermostat : Thermostat ;19 ...20 }21 }1 org ACMESmartHome implements SmartHome {23 workspace mainRoom {4 log = Logger ();5 majordomo = ACMEHomeAdmin ();6 }78 workspace bedroom {9 therm = ACMEThermometer ();10 cond = ACMEConditioner ();11 thermostat = Thermostat12 ( conditioner : cond13 thermometer : therm );14 ...15 }1617 }Fig. 5. Example of the definition of an organization model in simpAL (on the left) andthe a main organization file implementing the model (on the right).Finally, the explicit declaration of observable properties (in interfaces) and (hidden)state variables in artifact templates – the latter can be declared also localvariable in operations – allow for checking errors in the implementation of operationsabout the use of unknown observable properties/variables or about theassignment of values with a wrong type.3.4 Typing the Overall Program StructureIn simpAL we use the notion of organization to define the structure of the overallmulti-agent program, and we introduce then the type of an organization calledorganization model to explicitly declare the set of roles and interfaces which areused inside any organization of that type, and the set of workspaces that areavailable in any organization of that type. The declaration of the workspace caninclude then explicit declaration of the identifier (literals) of instances of artifactsand agents – along with their types – that are known to be available in thatworkspace 5 . Such identifiers are like global references that can be then referredin any agent script (so at to identify “well-known” agents to communicate with orartifacts to use) which explicitly declares to play a role R inside that organizationmodel.As a simple example, Fig. 5 shows the definition of the SmartHome, with amainRoom workspace hosting an artifact log of type Log and an agent majordomoof type HomeAdmin. Given this org model definition, then it is possible e.g. inthe KeepTemperature plan of the ACMEThermostat script to refer directly to theartifact log @ mainRoom (in spite of its actual implementation).5 In general, a workspace can contain at runtime also agents/artifacts not declared inthe model: their types, however, must be among the types described in the model.145