C.29:4.4.2 - From lens to local action

A consequence can direct a new observation, make a bounded comparison possible, expose a bottleneck or obstruction, or reject a candidate representation. State which of these happens and why. If the requested result is a plan, decision or other neighboring result, supply the mathematical consequence to that result under :4.4.6.

Worked local bottleneck: dense-state storage. A proposed dense pure-state representation for 50 qubits contains 2^50 complex amplitudes. At a stipulated 16 bytes per amplitude, its array alone requires 16 × 2^50 = 2^54 bytes, or 16,777,216 GiB. A 64 GiB implementation cannot hold it. Counting the representation’s elements and multiplying by storage per element identifies this bottleneck before implementation.

Recover the requested observable or property, then reconsider which structure must be represented. A restricted case, another representation or a justified approximation may change the resource demand; estimating each actual candidate’s storage and work can change the choice. When a particular representation change has been chosen, A.6.3.RT:4.1 supplies the conversion and preserved/lost-content check. Until a suitable domain algorithm is supplied, the present result is rejection of the dense implementation and a specific representation question. Ordinary storage arithmetic alone needs no lens card.