Welcome to Elogic!

Elogic is a web-based application for teaching logic. The application aids in teaching the syntax and semantics of first-order logic, with multiple exercise environments including a symbolisation interface, a model evaluator, and a natural deduction environment for constructing proofs.

Key Features:

About the project

One of the oldest intellectual disciplines in human history, logic is an essential background for many subjects, but especially mathematics, linguistics, cognitive science, philosophy, and computer science. An introduction to logic course is part of almost every university level philosophy curriculum in the world.

Elogic was designed specially for philosophy students who may be confronting symbolic logic for the first time. The application design puts emphasis on the user interface by making the functionality familiar, non-intimidating, and intuitive. This helps introductory students overcome common barriers stemming from “techno-” and “symbol-” phobias. In addition, the application provides automated feedback, and prompts, and helps to guide the student through each exercise.

Elogic supports core exercise types for first-order logic including Symbolisations, Derivations, and Models.

Symbolisations: Symbolisation exercises concern translations from English into propositional and first-order logic. A distinctive feature of the application is that it has a built-in evaluator that checks for logical equivalence between answers. So for example, any symbolisation that is logically equivalent to a correct symbolisation (modulo alphabetic variance) is recognised as correct. A further distinctive feature is that the system will recognise structural ambiguities (e.g. "Everyone loves someone"), so that a translation of either disambiguation will register as correct. The symbolisation exercises concern a fragment of English drawn from a restricted lexicon. The library already has over 100 sentences to translate (e.g. “No person who is either student or a teacher talked to Alfred”) and it continues to grow. We are happy to take suggestions.

Derivations: The interface for natural deduction proofs in propositional and first-order logic uses a variant of the “Fitch-style” system. In particular the system is coded to the Kalish and Montague variant from Parsons /An Exposition of Symbolic Logic/ (Support for other variants and systems are under construction.) The proof interface provides feedback and guides students through the more difficult parts of the system, such as instances of variable capture. The derivation exercise library has around 500 arguments to derive including all the theorems from Parsons' textbook.

Models: The model environment includes a specialised interface for building and checking truth-tables, as well as countermodel evaluators for both propositional and predicate logic. The truth-table environment provides detailed feedback such as “Oops...You haven't covered every possible case”, and so on. For the countermodel environment the system will check whether or not the model that the student provides is a countermodel for the relevant argument, and provide feedback.

Availability, and license arrangements

Elogic follows the Software as a Service model and is available to educational institutions. Please contact us for the details on how to get set up: hello@elogic.land.

Commitment to privacy and data security

We take privacy and data security seriously. We've aimed to be in compliance with the highest standards of the General Data Protection Regulation (GDPR). See our Privacy Policy.

How to contact us

Email us at: hello@elogic.land