# A Heterogeneous Battlefield Situation Information Sharing Method Based on Content
## 3 Entity Oriented General Description of Battlefield Situation Information
### Structure of the Concept-Logic Tree
#### 3.1.1 Concept-Logic Tree of Attributes  
As attributes of entities are closely related to corresponding entity classes, to construct a structured description model of attributes, the logical hierarchical relationship of entity classes needs to be described first. Following are several basic relations among \(C_{EC}\), and the reasoning rules based on them are shown in Table 2.  
* Inclusion: If \(\{EC_{i}{\rightarrow}A_{c_{i}c}\), \(EC_{j}{\rightarrow}A_{c_{j}c}\}\wedge A_{c_{i}c}{\subseteq}A_{c_{j}c}\), then \(EC_{i}\) include \(EC_{j}\), which is denoted as \(EC_{j}{\subseteq}EC_{i}\); while in this case, \(EC_{j}\) is also called a subordinate class of \(EC_{i}\). * Independence: If \(\{EC_{i}{\rightarrow}A_{c_{i}c}\), \(EC_{j}{\rightarrow}A_{c_{j}c}\}\wedge A_{c_{i}c}\cap A_{c_{j}c}=\emptyset\), then \(EC_{i}\) is independent of \(EC_{j}\), which is denoted as \(EC_{i}{\perp}EC_{j}\). * Intersection: If \(\{EC_{i}{\rightarrow}A_{c_{i}c}\), \(EC_{j}{\rightarrow}A_{c_{j}c}\}\wedge A_{c_{i}c}\cap A_{c_{j}c}\
eq\emptyset \wedge\{A_{c_{i}c}{\
subseteq}A_{c_{i}c}\), \(A_{c_{i}c}{\
subseteq}A_{c_{i}c}\}\), then \(EC_{i}\) and \(EC_{j}\) intersect each other, which is denoted as \(EC_{i}{\
subseteq}EC_{j}\). * Homology: If \(EC_{i}{\
subseteq}EC_{j}\wedge\{\exists EC_{k}{\rightarrow}A_{c_{k}c}\wedge A_{ c_{k}c}{\subseteq}(A_{c_{i}c}\cap A_{c_{j}c})\}(k\in\mathbf{N}\wedge k\
eq i \wedge k\
eq j)\), then \(EC_{i}\) and \(EC_{j}\) are homogenous, which is denoted as \(EC_{i}{\
subseteq}EC_{j}\). * Equivalence: If \(\{EC_{i}{\rightarrow}A_{c_{i}c}\), \(EC_{j}{\rightarrow}A_{c_{j}c}\}\wedge A_{c_{i}c}{=}A_{c_{j}c}\), then \(EC_{i}\) is equal to \(EC_{j}\), which is denoted as \(EC_{i}{\equiv}EC_{j}\). Figure 5: Relations among entities, entity classes, attributes, and states. Typically, we can use a tree structure to describe these relationships among entity classes explicitly, i.e., a classification tree of entity classes can be built based on the relationships among entity classes. **Definition 2** (entity class classification tree). : _Suppose \(CT_{\text{EC}}(V_{\text{EC}})\) is a tree with \(V_{\text{EC}}\) as the root node and all entity classes in the research field as its child nodes, while the nodes are organized by the logical relationships among entity classes._  
Figure 6 displays the basic structure of \(CT_{\text{EC}}(V_{\text{EC}})\), where \(V_{\text{EC}}\) can be viewed as a virtual entity class, which is used to represent the class with the highest degree of abstraction. The level of \(V_{\text{EC}}\) is assumed to be zero, and no actual attribute set or state set is attached to it. Besides, the attribute set of \(V_{\text{EC}}\) is denoted as \(A_{\text{EC}}\), which contains only the attributes that are common to all entities in the entity space such as the time-attribute and space-attribute. The state set of \(V_{\text{EC}}\) is denoted as \(S_{\text{EC}}\), which is regarded to be empty or only contains the state of \"exist\". Based on the structure of the entity class classification tree and the property inheritance relationship between the parent and the subclass, the attribute concept-logic tree can be obtained. **Definition 3** (attribute concept-logic tree). : _The attribute concept-logic tree is denoted as \(T_{\text{LEC}}(EC_{i})\), which is a tree with \(EC_{i}\) as the root node, and can be formally expressed as \(T_{\text{LEC}}(EC_{i})\) = \((EC_{i}(S^{\prime}_{\text{c}_{\text{i}}}\cup S^{\prime}_{\text{c}_{\text{i}}} \cup S^{\prime}_{\text{c}_{\text{i}}},A^{\prime}_{\text{c}_{\text{i}}},A^{ \prime}_{\text{c}_{\text{i}}},A^{\prime}_{\text{c}_{\text{i}}},\)\(\bigcup\)\(T_{\text{LEC}}(EC_{i})))\()\), where \(i\), \(j\in\mathbf{N}\), and \(EC_{\text{j}}\in\mathbf{C}_{\text{EC}_{i}}\).