Prawitz proved that the basic logical connectives \(\wedge ,\vee ,\rightarrow ,\bot \) are not interdefinable in intuitionistic logic. His proof relied essentially on treating negation as a defined connective, and a key lemma fails when \(\lnot \) is included as a primitive connective. I provide a new proof of this result that applies when negation is a primitive connective and which also shows that \(\wedge ,\vee ,\rightarrow ,\lnot \) are not interdefinable.
