 Lines may get marked at specific stages of a proof just to get unmarked at latter stages and vice versa. This mirrors the internal dynamics of defeasible reasoning. In order to define a consequence relation, a stable notion of derivability is needed. A formula derived at an unmarked line l in an adaptive proof from a premise set \(\Gamma\) is considered a consequence of \(\Gamma\) if any extension of the proof in which l is marked is further extendable so that the line is unmarked again. 