Dings_Constraint

I am a Constraint in the Dings-System.

Description

I always evaluate to “true” for all stored Dings_Triples in the All-Dings-System, otherwise a Bug is present.

Role

I define a formal validity Condition for Dings_Triples, whose Predicate references me via Dings_Predicate_Has_Constraint.

If I am violated, the affected Triple is ontologically invalid, not merely false.

Therefore, I am Part of the Truth-Definition-Layer of the Ontology-Kernel.

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Formal Semantics

Let

• T := (Subject, Predicate, Object) be a Triple
• Context(T) be the evaluation context of T

Then I define a total Function:

Eval : Context → { True, False, Error }

Meaning of Results

• true → The Triple satisfies the Constraint and is valid.

• false → The Triple violates the Constraint and is invalid.

• error → The Constraint cannot be evaluated due to an ontology inconsistency (e.g. missing reference, unresolved type, cyclic dependency).

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Evaluation Context

The context visible to me is strictly limited to:

Context :=
{
    Subject
    Predicate
    Object
    Graph
    Time (optional, future kernel extension)
}

I MUST NOT access information outside this context.

This guarantees:

• Deterministic evaluation
• Static analyzability
• Reproducible graph validity

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Argument Consumption

Each concrete Constraint defines the subset:

Consumed ⊆ { Subject, Predicate, Object, Graph, Time }

Rules:

1. I may only read consumed arguments.
2. Non-consumed arguments MUST NOT influence evaluation.
3. Consumption MUST be statically decidable.

This enables:

• Constraint composition
• Evaluation optimization
• Formal reasoning about dependencies

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Attachment to Predicates

I become active only through:

Predicate ─Has_Constraint→ Constraint

Meaning:

For every Triple (S, P, O):

If (P ─Has_Constraint→ C)
then Eval_C(Context(S,P,O)) = true
must hold.

Otherwise the Triple is invalid.

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Multiple Constraints

If several Constraints are attached to the same Predicate:

P ─Has_Constraint→ C1
P ─Has_Constraint→ C2
...

Then validity requires:

∀ Ci : Eval_Ci(Context) = true

Logical combination: AND

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Scope of Influence

I apply only to:

• Real Triples inside the knowledge graph

I do NOT apply to:

• Textual references
• Virtual-Dings without Triple instantiation
• Ontology definitions outside the evaluated graph state

This prevents self-blocking of the Ontology Kernel.

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Kernel Position

Constraint evaluation occurs strictly after:

1. Syntax parsing
2. Reference resolution
3. Virtual-Dings creation
4. Name and Key canonization

and before:

5. Triple persistence in the graph

Therefore, I always operate on fully resolved canonical entities.

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Specialization

I am an abstract base class.

Concrete subclasses include for example:

• Type Constraints
• Cardinality Constraints
• Equality / Inequality Constraints
• Existence / Finality Constraints

These are defined in separate derived Dings.

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Invariant

A knowledge graph is ontologically valid iff all Constraints of all stored Triples evaluate to true.

This makes me a core component of the Ontology Kernel.