MATH.20:10 - Architectural Rationale
The unknown is reached through another construction whose mathematical relation to it is tractable. Feasible witnesses, potential inequalities, inverse-map estimates and set inclusions give different ways to establish that relation. Their common structure is an order with a proved direction and operations that preserve the intended consequence.
Constructing bounds and choosing between alternatives have different results. The first supplies an inequality or enclosure; the second uses it with the purposes and costs of the work. This lets the same mathematical method serve proofs, computations and modeling without adding a separate preference system.
The gap is itself useful mathematical information. Matching attainable bounds can establish an optimum; a failed equality condition or two separating cases can show what prevents a narrower answer.