One cannot define the quantification and operations on knowledge without defining the entities that will generate and use the knowledge. An entity is generally considered as anything that exists. The main philosophical question related to existence is, how do we know if something exists? In response to this, we think anything that exists must possess a value. So, with respect to this research, we define an entity as follows:
In this section, we mathematically define different types of entities, their logical relationships and operations.
2.2.1. Description and Properties
We distinguish and define three types of entities: agent, target, and environment, together with their properties.
Definition 16.
An agent, g, is an entity that possesses cognitive property values.
The different cognitive properties an agent can posses are presented in
Figure 1. An agent can also be considered as a
cognitive actor in an environment.
Definition 17.
A target, t, is an entity that an agent seeks, and is define by a set of input and output property values, and the relationship value between the two properties.
The properties of the target represent the domains of the environment in which the target is found. The output domains define the existence of the target and are considered as the existential properties of the target. The input domains influence the existence of the target and are considered as the evidential properties of the target.
The process where an agent uses input properties of a target to act on the output properties of the target is called
Perception [
71,
72], and it is the main focus in conventional agent design. Whereas, the process where the agent seeks to reproduce the output properties of a target is called
Conceptualization [
72,
73]. In most conventional agent design, the output properties are given to the agent (with or without labels) during learning and testing, and this does not imply conceptualization.
To fully act on a target, an agent must not only identify the input and output properties of the target but also the relationship between them. Thus, the main goal of an agent during learning is to recreate the relationship between the input and output properties of a target. This is summarized in the axiom below.
Axiom 2.6. The value an agent attributes to the input-output relationship of a target is a property of the agent and defines the relationship between the agent and the target.
We define an environment entity, which acts as a container of agents and targets.
Definition 18.
An environment, e, is an entity which contains agents and targets and defines their relationships.
Environments may contain other environments which we group into:
community, world, universe, multiverse, and
infiniteverse. A community is an environment with agents and targets, a world is a collection of communities, a universe is a collection of world, a multiverse is a collection of universes, and infiniteverse is an infinite hierarchy of multiverse. We consider all environments as
containers as illustrated in
Figure 3.
We logically define these structural properties as follows:
, and , ,
where e is an environment entity, g is an agent entity, t is a target entity, Q is the set of entity types, is an entity, and q is a container or set of entities.
To support our operations on agent design, we define the following functional properties of the different entities.
where
is intelligence property, A is action property, C is cognitive value property,
is relationship between properties, and
is inherited property from the environment.
Generally, using the knowledge property, we can simply express the agent as follows:
where
g is an agent,
t is target of the agent,
y is a target output information,
X is the vector of target input information,
is action value (or belief) of the agent on the target,
is the intelligence (or parameters) of the agent that enables the action, and
is knowledge generated by the agent based on its action and the environment action
on the target.
where
,
X is input property,
Y is output property.
Generally, we can simply express the target as an entity of the environment as follows:
where
t is a target in an environment,
X is vector of properties of the environment that act as input (or evidential) properties of the target,
Y is vector of properties of the environment that act as output (or existential) properties of the target, and
is a property of the target that defines a logical relationship between
X and
Y.
where
is property of the environment,
defines the relationship between the properties of the environment, and
is inherited property from the environment container.
Also, depending on the content of the environment, its properties can be grouped into those of the agents , target and their relationship , i.e., .
Generally, we can simply express the environment as follows:
where
e is an environment,
is a vector of all properties of the environment, and
is a logical relationship define over all the properties of the environment.
Figure 4 shows the interaction between agents and targets in different environments.
After defining the entities and properties, we then define logical relations and operations on them. The next section answers questions about the equality, equivalence, superiority, inferiority, dependency, association, dissociation, and intersection of entities. For example, when are agents equal?
2.2.2. Logical Relationships Between Entities
We define different logical relationships between entities, where is entity property, indicates the logical relationship (∗) between entities and over the property , , and . Also, iff means `if and only if’, and ⊥ means logical independence.
i. Equivalence (≡)
Two entities are equivalent over a set of properties if at least one of the properties (weak equivalence) or all (strong equivalence) have same value and structure.
We distinguish two types of equivalence.
a) Agent equivalence: iff .
b) Target equivalence: iff .
Equivalent relationships must also be reflexive, symmetrical and transitive over the properties. Example of equivalent relationship between entities is an equality relationship.
ii. Equality (=)
Two entities are equal over a set of properties if at least one of the properties (weak equality) or all (strong equality) have same value. We distinguish two types of equality.
a) Agent equality: iff .
b) Targets equality: iff .
iii. Superiority (>)
One entity is superior over another entity on a set of properties if at least in one of the properties (weak equality) or all (strong equality), it has a greater value. We distinguish two types of superiority.
a) Agents superiority: iff .
b) Targets superiority: iff .
iv. Inferiority (<)
One entity is inferior over another on a set of properties if at least in one the properties (weak equality) or all (strong equality), it has a lesser value. We distinguish two types.
a) Agents inferiority: iff .
b) Targets inferiority: iff .
v. Dependency (→)
An entity depends on over a set of properties if at least one (weak dependency) or all (strong dependency) properties of are defined by those of . We distinguish two types of dependency.
a) Agents dependency: iff .
b) Target dependency: iff .
By definition, we can consider that, all entities depend on their properties.
.
Dependency between entities can be bidirectional,
iff .
vi. Conditional dependency()
It is a type of dependency where the relationship between the properties of the two entities is conditioned on one of the entities or a third entity. An entity is conditionally dependent on another entity over a set of properties if (the occurrence of) at least one property (weak condition) or all properties (strong condition) of are conditioned on those of , or those of a third entity . We distinguish two types of conditional dependency;
a) Agents conditional dependency: iff .
b) Targets conditional dependency: iff .
Conditional dependency can also be bidirectional,
iff .
If , we say the entities are conditionally equivalent over the property . That is, .
vii. Mutual dependency(⊸)
It is a type of dependency where the self relationships of the entities on their property are excluded from their conditional relationships.
An entity is mutually dependent on another entity over a set of properties if (the occurrence of) at least one (weak condition) or all the self properties (strong condition) of are excluded from its conditional relationship with those of , or those of a third entity .
.
Excluding their self-relationships imply that mutual dependency captures a bidirectional relationship between entities. Hence, Two entities in a mutual dependency over a property have a birectional equality over the property.
(reciprocity).
Similar to conditional dependency, mutual dependency can be established on the properties of targets and agents.
viii. Container (⊔ , □)
An entity q is a container to another entity over a set of properties if for these properties, is equal or inferior to q. iff .
Axiom 2.7. Containers can be defined based on their entities and entities can be defined based on their containers.
From Axiom 2.7 and the definition of a container, we can conclude that, all entities in a container depend on the container and all containers depend on their entities.
.
We distinguish two categories of containers and entities dependency relation, that is, coupling and cohesion.
ix. Coupling (⋈)
It defines the dependency between containers. A container entity is coupled with a container entity iff .
x. Cohesion (⨂)
It defines the dependencies between entities in a container. An entity is considered to be cohesive with an entity , iff . Cohesive dependency can exist between entities in same container or different containers. We distinguish two types of cohesion;
a) Local cohesion: and .
b) Remote cohesion: and .
Also, based on the dependency and exchange of properties between containers and their host, we can distinguish three types of containers; open, close and isolated containers.
xi. Open container (⊔)
A container q is open over a host h if values for some of q depend on h, i.e., , and or can be exchanged between q and h.
xii. Close container (□)
A container q is closed over a host h if values for some of q depend on h, i.e., , and or cannot be exchanged between q and h.
xiii. Isolated containers (□)
A container q is isolated over a host h if values for all of q is independent on h, i.e., , and or cannot be exchanged between q and h. In addition, entities can be considered as a container because even if they may not contain other entities, they contain at least some properties, making them property containers.
xiv. Referencing ()
A relationship where an entity uses another entity as its container or content in defining its property value.
Axiom 2.8. Any referencing to a referent equal to the referral on a value is insignificant (null) to the referral.
If .
Axiom 2.9. A referral will downgrade if it references a referent less significant than it on a value, and upgrade if otherwise.
If (downgrade),
if (upgrade).
Referencing can be considered as a relative relationship or a type of dependency of an entity on another entity.
In general, an agent can relate to different entities for different purposes to achieve a value, to some (e.g., targets) it builds a conditional relation, while to others (e.g., environments) it builds a reference relation. The operation on the relationships of an entity is important, and requires a logical construct, which we define in the following axiom.
Axiom 2.10. The operation on the relationships of an entity can be defined as a vector operation on the relationships.
For example, if entities and are non-referentially (e.g., conditionally, mutually, jointly, etc.) related to independently, then any referential relationship we define between and on will be equal to the vector sum of their individual relationships on .
Let , , and .
Then, using an n-dimensional Euclidean vector space of , on a relationship between entities, we propose that,
For to exist during non-collinearity, the environment of one entity needs to be transformed to the environment of the other, leading to a collinear situation.
Furthermore, with collinearity, other vector algebra operations such as operations on vector magnitude can be evaluated easily using vector rules such as the cosine rule.
where
.
In such case, the angle between the non-referential (i.e., absolute) values of two entities about a third entity represent their referential (i.e., relative) relationships about the entity.
Conjecture 2. The angle between any two entities and on is a measure of their referential relationship.
These relationships between non-referential and referential values of entities are represented in
Figure 5.
For a relationship over space and time, we shall apply hyperbolic functions to the Euclidean vector in a future publication to present important effects of time and space on cognition. The relationships can also be represented using tensors on the euclidean and non-euclidean (e.g., hyperbolic) space.
2.2.3. Logical operations between entities
We define three types of operations (association, dissociation, intersection) between containers and entities.
i. Operations Between Containers
a) Association(∪) of containers
This involves the union of the entities of many containers to form a new container.
.
b) Dissociation (-) of containers
This involves the separation of a container from another container to form a new container.
.
c) Intersection (∩) of containers
This involves the intersection of many containers to form a new container based on their equivalent entities. .
ii. Operations between entities
a) Association (∪) of entities
This involves the union of the properties of many entities to form a new entity.
.
b) Dissociation (-) of entities
This involves the separation of an entity from another to form a new entity.
.
c) Intersection (∩) of entities
This involves the joining of many entities to form a new entity based on their equivalence properties.
.
iii. Operations between properties
This involves operations between the values of the properties of entities, rather than the entities themselves. Due to the dependency possibility of the properties, we use probability logic operations [
79] to define the operations between properties. Nevertheless, other logic, such as, functional, fuzzy, symbolic, etc., can also be used.
Concerning property and value, the main difference between them in this paper is that, a property is a variable (or container) that holds a value which can be optimized within the property, while a value is the content of a property and defines the nature of the property. Values can be static, dynamic, discrete, continuous, etc.
In this section, we presented three types of entities and defined the properties, relationship and operations they can posses. In the next section, we will introduce the quantification of the knowledge property and different cognitive properties related to it.