Section DerivableRulesFromSequentCalculus.
Context {L: Language}
{GammaD: Derivable L}
{bSC: BasicSequentCalculus L GammaD}.
Context {minL: MinimumLanguage L}
{minSC: MinimumSequentCalculus L GammaD}.

Theorem deduction_theorem:
forall (Phi: context) (x y: expr),
Union _ Phi (Singleton _ x) |-- y <->
Phi |-- x --> y.