Presumptions and fictions: corpus forms

Breakdown of real fragments: package identifier, human act name, form rating (exemplary / debatable / wrong form choice) and why.

OverviewBoundariesCorpus formsPitfalls

Law

1. EU air passenger rights — presumption with a contrary exception (exemplary)

Package eu.transport.air_passenger_rights (EU air passenger rights, Regulation 261/2004), cancellation:

Arxo Law

presumption PassengerUninformedUnlessCarrierProves(p: Passenger, f: Flight) {
    ...
    when confirmed_reservation(p, f) and cancellation(f);
    presume passenger_treated_as_uninformed(p, f);
    unless carrier_proved_notification(p, f)
        then not passenger_treated_as_uninformed(p, f);
}

Exemplary: the burden of proving notification is on the carrier (ground + presumption + exception with priority). The contrary then not … clause gives the rebuttal victory with a Refuted inference — unlike the bare clause of the section’s teaching example, which gives Not established, not refuted. The “bare vs contrary” pair in one research is deliberate.

2. German Civil Code — possessory ownership presumption (exemplary)

Package de.bgb.besitz_eigentum (German Civil Code, possession and ownership):

Arxo Law

presumption VermutungDesEigentumsFuerDenBesitzer(s: Sache, p: Person) {

Possession as the ground of the ownership assumption. Exemplary as a proof scheme; exception details are in the package body.

3. German Civil Code — recorded-right presumption (exemplary)

Package de.bgb.besitz_eigentum (German Civil Code, registered rights) — presumption VermutungDesEingetragenenRechts(r: Recht, p: Person). A land-register entry as the ground. Same form, different ground — the presumption scheme stable across grounds.

4. Saudi tort — causation presumption (exemplary)

Package sa.civil_transactions.tort_enrichment (Saudi civil transactions, tort) — presumption DirectActorCausedDamage(a: HarmfulAct); vicarious liability — presumption OwnerIsKeeper(p: Person, t: Thing). Presumptions as burden allocation in tort — a subject-matter pair to the procedural EU261 form.

Legal history and custom

5. Calendar Act 1750 — pure fiction (exemplary)

Package gb.corpus.calendar_act_1750 (Calendar Act 1750, Great Britain), preserved natural day:

Arxo Law

fiction FairOrMartPreservesNaturalDay strict {
    ...
    for e: FixedEvent;
    when held_with_fair_or_mart(e);
    deem natural_day_category(e);
}

A fair “holds to the natural day” — equation without “if”: strict strength mandatory and present. Exemplary.

6. Queue customary law — announced-absence presumption (exemplary)

Package usus.corpus.ochered (queue customary law) — presumption AnnouncedAbsenceHoldsThePlace(q: Queue, p: Person). Announced absence holds the queue place until… — a grounded default in customary law.

Science

7. Doctrine chemistry — presumption and fiction side by side (debatable)

Package chem.rules (doctrine chemistry rules) — presumption ChloridePresumedSoluble(s: Salt, c: Cation); oxidation — fiction BondsDeemedIonic strict. Debatable, not exemplary: the “counts as soluble” link nowhere records whether the exception list is closed (see the negation section’s note on debatable solubility): it is unclear whether Not established, not refuted means “soluble” or “not checked”. The ionic-bond fiction is exemplary as a device (modelling equation).