Section Sound.
Context {L: Language}
{minL: MinimumLanguage L}
{pL: PropositionalLanguage L}
{MD: Model}
{SM: Semantics L MD}
{tminSM: TrivialMinimumSemantics L MD SM}
{tpSM: TrivialPropositionalSemantics L MD SM}.

Lemma sound_orp_intros1:
forall x y m,
m |= x --> x || y.