1. Logic classification

Non-classical (formal) logics refer to the types of logical systems that differ from classical logics, i.e. from propositional logic and predicate logic [AF 89] .

A logic can have a more or less rich vocabulary (i.e. an alphabet with more or less symbols), a more or less strict syntax (i.e. an expressive power leading to more or less well-formed formulas), a more or less broad semantics (i.e. interpretations allowing more or less validities) and a more or less restrictive logical calculus (i.e. demonstrations establishing more or less theorems).

These differences...