Module validate 

Reference shape satisfaction G, v ⊨ φ and schema validation G ⊨ S (doc 00 §3–§4, Table 2). This is the conformance oracle: the optimized engines in later layers must agree with it.

Two evaluators share the logic: [holds] returns a bare bool (used for target selection and counting), while [explain] returns the specific atomic constraints that failed, with the value node and path at which they failed — enough for per-constraint reporting. The ∀π = ∃≤0 π.¬φ encoding lets a failed universal drill straight into the offending value node’s inner constraint.

Structs

NonStratifiable

The schema is not stratifiable: it recurses through genuine negation, so it has no defined 2-valued semantics (docs/03-recursion-semantics.md). We diagnose rather than guess. Carries the offending shape components.

Reason

A single failed atomic constraint.

ValidationOutcome

The outcome of validating a data graph against a schema.

Violation

One focus node that failed its statement’s shape, with the reasons why.

Enums

ValidationGraphMode

Which RDF graph(s) validation uses for focus discovery and evaluation.

Functions

focus_nodes

The focus nodes selected by a selector.

validate

Validate data against schema.

validate_graphs

Validate split data and shapes graphs using the selected graph mode.

validate_graphs_with_mode

Validate split data and shapes graphs using an explicit graph mode.

validate_plan

Validate using a PhysicalPlan (Layer 5): focus nodes come from compiled FocusSources (so class targets seed backward from the constant instead of scanning every node) and checks run over the plan’s cost-ordered arena. The result is identical to validate on the same schema — the W3C harness cross-checks this.

validate_plan_graphs

Validate a physical plan over split graphs using the default graph mode.

validate_plan_graphs_with_mode

Validate a physical plan over split graphs using an explicit graph mode.

validate_plan_with_context

Validate plan focus nodes from data against the supplied execution context.

validate_with_context

Validate focus nodes from data while evaluating paths, class hierarchy, and SPARQL against context. For split data/shapes inputs, context should be their RDF union.