B.5.RC:3 - Forces · fpf.tools

Force	Tension
Required result and available means	Working backward keeps the desired result in view; working forward reveals what the available operations can actually produce.
Source fidelity and useful invention	Filling a gap may solve the task, but the added operation then needs its own justification and must remain distinguishable from what the source supplied.
Properties and ways of obtaining an object	A property can guide construction or follow from it. The next use determines whether an existence result suffices or an instance must be obtained.
Shared prerequisites and execution order	Several steps may use the same object, and one step may need several results together. A simple list can hide either relation.
Small case and reusable method	A small case exposes missing operations cheaply; broader use depends on which conditions and operations survive the change of case.