The Proof Machine (2016)

The Incredible Proof Machine is an interactive visual tool that allows users to create formal proofs in various logics (propositional, predicate logic, etc.) by dragging and dropping blocks and connecting them, without requiring knowledge of complex theorem prover syntax. The tool provides real-time feedback by turning the conclusion green when a valid proof is completed, and includes keyboard shortcuts and customization options to help users learn and practice logical reasoning.