MMP.9:10 - Architectural Rationale

Reduction is organized around the requested result and the source law’s unclosed contribution. This makes the choice between retained state, memory, approximation and bounds depend on what each construction obtains. Beginning with one favored approximation would select what to discard before establishing its effect.

A.3.3.PI supplies the question-relative information test. This method develops the subsequent mathematical construction of a replacement contribution. C.29.1 supplies the common exact-or-bounded transfer and error propagation; those rules also apply to constructions outside model reduction.

Linear response, nonlinear aggregation and fast transients require different constructions. A new source law requires deriving its own discarded contribution; it need not resemble one of these examples. When the deriving operation itself requires a further subject method, retain that mathematical dependency rather than presenting a technique’s name as an already obtained closure.