A gap in the relationship between an argument's premises and its conclusion such that, even if every premise is granted as true, the conclusion does not necessarily follow. Reasoning flaws never reside in the premises themselves or in the conclusion itself — only in the support relationship between them. On the LSAT, the test-taker accepts the premises as given and asks whether they actually justify the conclusion, framing the gap as "the author fails to consider..." or "the author takes for granted that..."