A `subject` is reported as an ordinary part with no direction (and no type in a requirement def), and inherited `result`/`verdict` parameters are not listed

Start with internal/semantic/symbols/builder.go, especially the *ast.SubjectMember case, and trace how parameter direction, subject typing, and inherited return parameters reach attributes(). Reproduce with the supplied Python example or the C01 cases C01-055..064 in sysmlv2-tests; inspect the Go API path too, since the issue reports the same behavior there. Done means the listed parameters and metadata match the expected table for definitions and specializations.

This issue was written with AI help. The model and the reproduction were run against the version below.

What happened

package P {
    private import ScalarValues::*;
    part def Thing;
    constraint def Cons     { in x : Real; x > 0 }
    requirement def Req     { subject s : Thing; in x : Real; }
    use case def UC         { subject s : Thing; }
    analysis def An         { subject s : Thing; return r : Real; }
    verification def Ver    { subject s : Thing; }
}

import opensysml
m = opensysml.loads(SRC)            # m.ok is True, no diagnostics
for qn in ["P::Cons", "P::Req", "P::UC", "P::An", "P::Ver"]:
    d = m.get(qn)
    for c in d.children():
        print(qn, c.name, c.kind, dict(c.metadata),
              c.type_facts.resolved_id if c.type_facts else None)
    print(qn, "attributes:", [(a.name, a.metadata.get("direction")) for a in d.attributes()],
          "withheld:", d.withheld_library_attributes)

P::Cons x referenceUsage {'type': 'Real', 'visibility': 'default', 'direction': 'in'} ScalarValues::Real
P::Cons attributes: [('x', 'in')] withheld: 58
P::Req s partUsage {'visibility': 'default'} None
P::Req x referenceUsage {'type': 'Real', 'visibility': 'default', 'direction': 'in'} ScalarValues::Real
P::Req attributes: [('x', 'in')] withheld: 58
P::UC s partUsage {'type': 'Thing', 'visibility': 'default'} P::Thing
P::UC attributes: [] withheld: 55
P::An s partUsage {'type': 'Thing', 'visibility': 'default'} P::Thing
P::An r referenceUsage {'type': 'Real', 'visibility': 'default', 'direction': 'out'} ScalarValues::Real
P::An attributes: [('r', 'out')] withheld: 55
P::Ver s partUsage {'type': 'Thing', 'visibility': 'default'} P::Thing
P::Ver attributes: [] withheld: 56

Three things are wrong with the subject, and one with the result parameters:

1. The subject is a partUsage. The symbol builder makes it one on purpose (internal/semantic/symbols/builder.go, case *ast.SubjectMember: "Create a part usage symbol (subject is structural usage like part)"). In SysML a subject is a ReferenceUsage (SubjectUsage : ReferenceUsage). It is owned through a SubjectMembership, which is a ParameterMembership, so it is a parameter of the case or requirement.
2. The subject has no direction. Every other parameter carries direction in its metadata. A parameter with no written direction is in: KerML ParameterMembership::parameterDirection() gives in, and Feature::direction takes it from there. Nothing in the Symbol marks s as the subject either, so a client cannot tell subject s : Thing; from part s : Thing;.
3. In a requirement def the subject has no type. subject s : Thing; in Req reports no type metadata and an empty type_facts.resolved_id. The same declaration in UC, An and Ver reports P::Thing. This happens whether or not the subject is the first member.
4. Inherited result and verdict parameters are not listed. A constraint def and a requirement def inherit the result : Boolean return parameter, a use case def its result, and a verification def its verdict (which redefines result). They come from the standard library, so attributes() withholds them along with the rest of the library members (withheld_library_attributes). A declared return r is listed, as An shows. Leaving out library noise such as self or subparts is reasonable. The return parameter is part of the definition's signature, though, and should be listed like r.

Expected

The parameters, with their directions:

The subject is a referenceUsage with direction: in and something that marks it as the subject. A metadata key such as subject: true would do. The same applies to the specializing definitions (requirement def SubReq :> Req; and so on), which inherit these parameters.

For comparison, the SysML v2 Pilot Implementation (0.64.0-SNAPSHOT, commit 378a8700c) and sysml-toolkit (v0.11.3, ResolvedModel compatibility reader) list exactly these parameters, in both the definitions and their specializations.

Version

OpenSysML develop at 1a8e4927dc (2026-11-05), built locally: sysml-grpc nightly-153-g1a8e4927dc, Python client from client/python. The Go API (client/opensysml) fails the same cases.

Related

#1961 is about members not being listed through a typing usage or a specialization. Here the definitions are read directly.

Found by

The test suite at https://github.com/hideo67/sysmlv2-tests, matrix C01 (behavioral definitions), model test-suite/data/models/C01.sysml. Failing cases C01-055..064: the parameters of Cons, Req, UC, An and Ver and of their specializations SubCons ... SubVer.