Formal explanations as logical derivations

According to a longstanding philosophical tradition dating back Aristotle, certain proofs do not only certify the truth of their conclusion but also explain it. Lately, much effort is being devoted logically characterise explanatory relation grounding, especially by proof-theoretical means. Nevertheless, no thorough investigation resulting notion formal explanation exists. We show that explanations can be seen as logical derivations particular kind and study interactions between grounding rules, derivations. define minimal calculus captures both derivability, normalisation procedure rules are proof-theoretically balanced with respect elimination rules. The introduced enables us combine explanations, distinguish parts from non-explanatory parts, compose in order construct chains consecutive steps.