Definition
The obstruction-class that names when local-consistency does NOT lift to global-coherence — sheaf cohomology as received-ordinance. Named from sheaf cohomology (Leray 1946, Grothendieck 1957) + Sumerian me (received-ordinance). The HARMONE-failure-diagnostic: the measurable obstruction-form that coherence-failures take. When every local patch is consistent but the whole cannot be, sheafme is what stands in the way.