Formal System

We call $⟨\mathcal{L},\mathcal{K},\models ,⊢⟩$ a formal system if $\mathcal{S}=⟨\mathcal{L},\mathcal{K},\models ⟩$ is a Logical System and the relation $⊢$ is a Derivation Relation for $\mathcal{S}$.

We can use Calculus-Derivation to create proofs in such a system.

Logical System + Derivation Relation = Formal System