Formalizing the logical consequence in classical logic

The question of formal formulation (without analyzing the specific content of variables) of the logical consequence «A⊧B» is not still finally answered. This is due to the known difficulties. Firstly, the logical consequence takes place in conditional (implicative) statements which, if they are true, may express logical consequence or may not. Secondly, conditional statements can be true even when their antecedents and consequents are not related to each other according to their senses. Thirdly, the problem of what is called «paradoxes of material implication» is imposed on answering the question of the logical consequence: it is known that the implication is true, as in the case if the falsity implicates the truth ("The truth follows from anything") as in the case when the arbitrary expression is derived from the contradiction («contradictione (sequitur) quodlibet (ECQ)» («from contradiction, anything (follows)»).