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zorch.stage

Separately deployable roles for conditional proof reductions.

A stage is one mathematical claim-reduction contract. Its prover and verifier are separate runtime objects so role-specific capabilities, especially proving and verification keys, never need to share an object.

The roles are structural, like ProverRound/VerifierRound and Transcript: an adapter or a wrapper conforms by shape, without inheriting. Their members are @abstractmethod, so a class that does subclass one fails loudly at construction if it leaves a role method unimplemented — structural conformance for foreign types, nominal enforcement for its own implementers.

TrivialClaim dataclass

The claim that holds by construction, so nothing remains to prove.

A stage reducing to this is a complete argument rather than one link in a chain: an argument of knowledge is exactly a reduction to the trivial claim.

Source code in zorch/stage.py 
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@dataclass(frozen=True)
class TrivialClaim:
    """The claim that holds by construction, so nothing remains to prove.

    A stage reducing to this is a complete argument rather than one link in a
    chain: an argument of knowledge is exactly a reduction to the trivial
    claim.
    """

ProveResult dataclass

Bases: Generic[ReducedClaim, ReductionProof, TranscriptT]

A reduced claim, its conditional reduction proof, and the transcript.

Source code in zorch/stage.py 
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@dataclass(frozen=True)
class ProveResult(Generic[ReducedClaim, ReductionProof, TranscriptT]):
    """A reduced claim, its conditional reduction proof, and the transcript."""

    reduced_claim: ReducedClaim
    reduction_proof: ReductionProof
    transcript: TranscriptT

VerifyResult dataclass

Bases: Generic[ReducedClaim, TranscriptT]

The verifier-derived reduced claim, advanced transcript, and verdict.

Source code in zorch/stage.py 
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@dataclass(frozen=True)
class VerifyResult(Generic[ReducedClaim, TranscriptT]):
    """The verifier-derived reduced claim, advanced transcript, and verdict."""

    reduced_claim: ReducedClaim
    transcript: TranscriptT
    ok: Array

ProverStage

Bases: Protocol[Claim_contra, Witness_contra, ReducedClaim, ReductionProof, TranscriptT]

The prover role of one conditional claim reduction.

The transcript parameter carries the caller's concrete type through the reduction; omit it and it is the base Transcript.

Source code in zorch/stage.py 
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class ProverStage(
    Protocol[Claim_contra, Witness_contra, ReducedClaim, ReductionProof, TranscriptT]
):
    """The prover role of one conditional claim reduction.

    The transcript parameter carries the caller's concrete type through the
    reduction; omit it and it is the base `Transcript`.
    """

    @abstractmethod
    def prove(
        self,
        claim: Claim_contra,
        witness: Witness_contra,
        transcript: TranscriptT,
    ) -> ProveResult[ReducedClaim, ReductionProof, TranscriptT]: ...

VerifierStage

Bases: Protocol[Claim_contra, ReducedClaim, ReductionProof_contra, TranscriptT]

The verifier role of the same conditional claim reduction.

Source code in zorch/stage.py 
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class VerifierStage(
    Protocol[Claim_contra, ReducedClaim, ReductionProof_contra, TranscriptT]
):
    """The verifier role of the same conditional claim reduction."""

    @abstractmethod
    def verify(
        self,
        claim: Claim_contra,
        reduction_proof: ReductionProof_contra,
        transcript: TranscriptT,
    ) -> VerifyResult[ReducedClaim, TranscriptT]: ...