Definition
A105: “Fidelity ≈ preservation of selected observables and structural symmetries. The approximation symbol is important: this is a proposed operational criterion, relative to a selected class of observables, not a universal identity.” It “formalizes the distinction between an exactly preserved communicative observable and one that drifts gradually through repeated reconstruction” (CLAIM-107).
What it is not
Not a term of TERM-010. The manuscript §4 separates exact preservation, equivariance (TERM-004), approximate preservation and reorganization (CLAIM-113), and §6 gives the distortion functional. The two notions sit side by side and are never related: a transport can score well on L and break a symmetry, or the reverse.