Axioms
Rules
R1.
$\vdash A$
$\vdash A \rightarrow B$
$\vdash B$ Modus Ponens
R2.
$\vdash A$
$\vdash B$
$\vdash A \land B$ Adjunction
R3.
$\vdash A \rightarrow B$
$\vdash (B \rightarrow C) \rightarrow (A \rightarrow C)$ Rule Suffixing
R4.
$\vdash A \rightarrow B$
$\vdash (C \rightarrow A) \rightarrow (C \rightarrow B)$ Rule Prefixing
R5.
$\vdash A \rightarrow \neg B$
$\vdash B \rightarrow \neg A$ Rule Contraposition