contact, contacts, series, processes, boundaries, change, changes, transition, agents, nature, boundary, forms, zone, forces, sequence, relationship, types, character, work, transitions, agent, process, differences, zones, relationships, order, increase, phases, stages, relations, ontology, tops, passage, facies, difference, base, steps, soils, effects, tests, variation, terms, features, property, view, profiles, succession, borders, approach, margins, variations, sets, upper, parallelism, distinctness, spectrum, relation, varieties, pattern, sequences, top, measures, eon, valvuloplasty, properties, agencies, compound, perspective, scale, scheme, deposits, profile, genera, rocks, bedding, approaches, approximation, characters, bases, landforms, categories, ethic, color, plain, theories, exceptions, climax