Variable a : Bool Variable b : Bool -- Conjunctions Show a && b Show a && b && a Show a /\ b Show a ∧ b Show (and a b) Show and a b -- Disjunctions Show a || b Show a \/ b Show a ∨ b Show (or a b) Show or a (or a b) -- Simple Formulas Show a => b => a Check a => b Eval a => a Eval true => a -- Simple proof Axiom H1 : a Axiom H2 : a => b Check @MP Show MP H2 H1 Check MP H2 H1