The difference between the name AV (gematria 72) contained in AV, SaG (gematria 63) and MaH (gematria 45) and that contained in BaN (gematria 52).
BaN has only overall AV, because BaN receives, does not act. The active expansions (AV, SaG, MaH) carry particular AV; BaN carries only the general form.
Op. 56 specifies a structural feature of the four-expansions arithmetic. Each expansion contains AV in some form, but the form differs depending on whether the expansion is active or receptive. BaN is purely receptive; it does not act; it therefore carries only the overall AV, not the particular AV that the active expansions carry.
The distinction matters because it explains why BaN, despite being one of the four expansions, has a different operational identity than AV/SaG/MaH. The active expansions do something — radiate, govern, build, repair. BaN receives what they do. Its identity is not less than the others, but it is of a different kind: receptive rather than active.
Overall AV in BaN means the general form of AV is present, holding the structural integrity of the BaN-receiver. Particular AV in the active expansions means the operational specifics are also present, varying by what the expansion is doing at the moment.
This sets up the operational vocabulary of the rest of the book. When Klach later says every Partzuf is built of MaH and BaN (Op. 90), the receptive-active pairing of MaH (active) and BaN (receptive) is what produces the Partzuf's operational identity. When the unique arrangement of MaH and BaN in each Partzuf is named (Op. 84), the active-receptive asymmetry is what gives each Partzuf its distinctive concealed identity.
Op. 80 (BaN and MaH as the root of all defects and repairs through foreknowledge) operationalises the active-receptive asymmetry at the foreknowledge level. The unique-arrangement doctrine of Op. 84 is the structural form of Op. 56 generalised across the named-Partzuf walk.