sysml-validation

name	sysml-validation
description	Validate SysML v2 / KerML textual notation (.sysml / .kerml, not UML) for syntactic and structural correctness against the grammar and metamodel, and explain any violations with fixes. Use when the user provides SysML v2 or KerML textual notation to check, or asks whether a snippet is valid.

SysML v2 validation

Check SysML v2 / KerML textual notation against the documented grammar and metamodel, then report findings with locations and corrections.

Knowledge base

• knowledge/textual-notation/index.md – the grammar summary (declaration forms, membership & visibility, relationship operators) and keyword reference. Start here for syntax rules.
• knowledge/textual-notation/examples/ – worked valid examples (each links the metamodel elements it uses); knowledge/textual-notation/fixtures/ – the valid/invalid regression suite.
• knowledge/metamodel/ – the combined KerML + SysML v2 metamodel: elements/<Metaclass>.md for structural constraints, index.json (or index.md) for fast name → element lookup.
• knowledge/spec/ – normative clauses to cite. Git-ignored / generated locally (see tools/spec-extract); if it is empty, cite the metamodel/grammar instead and note the spec text is unavailable rather than inventing a clause.

What to check

Syntax (against the grammar reference)

• Every declaration is terminated by ; or has a { } body; braces/brackets/parentheses balance.
• Names are not reserved keywords unless quoted ('name'); keywords are spelled and placed per the reference.
• Relationship operators are correct: : (typing / defined by), :> (specializes / subsets), :>> (redefines), ::> (references), => (crosses). = binds a value, not a type.
• Multiplicity is well-formed ([lower..upper], [n], [*]).

Structural / semantic (against the metamodel)

• A usage is typed by a definition of the right kind (e.g. a part by a part def).
• redefines / subsets / specialization targets resolve to a feature or type reachable through a specialized type; multiplicity bounds satisfy lower <= upper.
• Member names are unique within their namespace; required features/parameters are present.

Procedure

1. Parse structurally: declarations, memberships, relationships, keywords (per the grammar summary).
2. Run the syntax checks, then the structural checks against knowledge/metamodel/elements/.
3. For each issue report location, the violated rule, why it is wrong, and a corrected snippet; add a knowledge-base reference (metamodel element or spec clause) for non-obvious rulings.
4. If nothing is wrong, state that the notation is valid.

The knowledge/textual-notation/fixtures/ suite is the reference for expected outcomes: valid fixtures should yield no findings; each invalid fixture documents the finding to produce.

Limits

This reasons from the documented grammar and metamodel; it is not the pilot-implementation compiler. When a definitive ruling needs the real parser, say so rather than guessing.

For larger inputs, delegate to the sysml-validator subagent.