The logic is the sentential logic defined in the language with just implication→ by the axiom
of reflexivity or identity “” and the rule of Modus Ponens “from φ and to infer ψ”. The theorems
of this logic are exactly all formulas of the form. We argue that this is the simplest
protoalgebraic logic, and that in it every set of assumptions encodes in itself not only all its
consequences but also their proofs. In this paper we study this logic from the point of view of
abstract algebraic logic, and in particular we use it as a relatively natural counterexample to�…

Erratum to <i>JM Font, The simplest protoalgebraic logic</i> … Erratum to JM Font, The
simplest protoalgebraic logic Josep Maria Font ∗ …