Whether...or Examples

difference between Logic and Logic

The logic is understood generally as a formal science , in the sense that its object of study, that of which deals are reference entities of formal or abstract.
In reality there are many logical, diverse nature and scope.
But if logic is understood that discipline that deals with studying the structure of the arguments we see that a form of reasoning is formal in the sense that it lacks a definite interpretation or, in other words, it contains variables (eg propositional letters) that can take different meanings, in fact infinite.
For example if you say "All A is B", "A" and "B" are formulas that can be replaced, in fact interpreted in infinite ways. For example, "all Madrid is English", or "every raven is a bird."
In contrast, the metalogic is a discipline that aims to study in the logic : it is a metadiscipline, a discipline that studies other discipline.
Thus, for example, contradictoriness not called in a formal system consistency. So the question of whether the logic is consistent is typical of the metalogic.
It is possible to analyze semantic aspects of logic (eg first order logic) and in that sense a reflection on the meaning of logical connectives will be a matter of metalogic, or metalogical.