# Towards Agent Organizations Interoperability: A Model Driven Engineering Approach
## 4 Abstract Conceptual Structure of Organizational Models
### Normative Dimension
#### 4.4.2 Particularities  
In ISLANDER, norms are written as logical expressions in accordance with the format:  
\((s_{1},\gamma_{1})\wedge...\wedge(s_{m},\gamma_{m})\ \wedge\ e_{1}\wedge...\wedge e_{n}\ \wedge\
eg((s_{m+1}, \gamma_{m+1})\wedge...\wedge(s_{m+n},\gamma_{m+n}))\ \rightarrow\ obl_{1}\wedge...\wedge obl_{p}\)  
where \((s_{1},\gamma_{1})\),..., \((s_{m+n},\gamma_{m+n})\) are pairs of _scenes_ and _illocution schemes_, \(e_{1}\),..., \(e_{n}\) are _boolean expressions_ over illocution scheme variables, \(\
eg\) is a _defeasible negation_, and \(obl_{1}\),..., \(obl_{p}\) are _obligations_. \"The meaning of these rules is that if the illocutions \((s_{1},\gamma_{1})\),..., \((s_{m+n},\gamma_{m+n})\) have been uttered, the expressions \(e_{1}\),..., \(e_{n}\) are satisfied and the illocutions \((s_{m+1},\gamma_{m+1})\),..., \((s_{m+n},\gamma_{m+n})\) have _not_ been uttered, the obligations \(obl_{1}\),..., \(obl_{p}\) hold\" ([48] p. 38).  
In OPERA, norms are specified using logical expressions written in a formalism called LCR (_Logic for Contract Representation_). There are three types of norms: _Obligations_, _permissions_ and _prohibitions_. The following excerpt from ([27] p. 149) summarizes the syntax for writing these modalities.  
<Norm>::= OBLIGED(<id>,<Norm-Form>)|PERMITTED(<id>,<Norm-Form>)| FORBIDDEN(<id>,<Norm-Form>)  
OBLIGED(<id >,<Norm-Form>) represents an obligation of the agent playing the role referenced by <id> in achieving the state <Norm-Form> described as an LCR formula ([27] chapter 4). Based on the notion of _obligation_, the concepts of _permission_ and _prohibition_ are defined. A permission PERMITTED<id>,<Norm-Form>) is an abbreviation for \(\
eg\)OBLIGED(<id>,\(\
eg\)Norm-Form>).  
Finally, in MOISE+, the general concept of _norm_ is translated into the notion of _deontic relations_ that link _roles_ to _missions_. There are two types of deontic relations, _permissions_ and _obligations_:  
\"A permission _per_(\(\rho\), \(m\), \(tc\)) states that an agent within the role \(\rho\) may be committed to the mission \(m\). Temporal constraints (\(tc\)) are established for the permission, that is, they determine a set of time periods when the permission is valid... An obligation \(obl(\rho\), \(m\), \(tc\)) states that an agent within the role \(\rho\) is required to commit to the mission \(m\) in the time periods determined by \(tc\).\" ([49] pp. 46-47)  
In this case, the normative expressions _per_(\(\rho\), \(m\), \(tc\)) and \(obl(\rho\), \(m\), \(tc)\) are less comprehensive than what is found in OPERA and ISLANDER.  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Class** & **Description** \\ \hline NSpec & Represents the concept of _normative specification_, i.e., organizational specifications restricted to the normative dimension. \\ NormDef & Central part of a normative specification. Represents the definition of a _norm_. In general, norm \\  & definitions are characterized by a _normative expression_ (attribute NormDef::normExp) that refers to \\  & elements found in the structural, functional and dialogical dimensions. The form and meaning of \\  & the normative expression vary considerably in the organizational models analyzed. Abstracts the \\  & concepts of _deontic relation_ found in MOISE +, and the particular concepts of _norm_ found in \\  & ISLANDER and OPERA. \\ \hline \hline \end{tabular}
\end{table}
Table 7: Normative specification pattern: Class description.