 We need some notational conventions before engaging in the precise definition of algebraizable logic. Given a set of equations \(\iEq(p)\) in one variable and a formula \(\phi\), let \(\iEq(\phi)\) be the set of equations obtained by replacing in all the equations in \(\iEq\) the variable \(p\) by \(\phi\). If \(\Gamma\) is a set of formulas, let