This is a gentle introduction to the weak completion semantics, a novel cognitive theory which has been successfully applied to a number of human reasoning tasks. In this paper we do not focus on formalities but rather on principles and examples. The reader is assumed to be familiar with classical propositional logic and the suppression task.

Despite several differences between civil law and common jurisdictions, today’s modern succession is based on Roman law, which requires strict formal rules for will-making. However, a historical perspective demonstrates that there slow but continuous shift away from formalism. In fact, form’s superiority over substance diminishing, testamentary formalities are mellowing. Yet legislative interve...