Synthesis Phase

The Synthesis Phase is the fourth of the nine conventionally numbered phases of a Cartographic Synthesis, commencing upon the closure of Comparative Synthesis and concluding with the opening of Doctrinal Integration. It is during the Synthesis Phase alone that contradictory maps of a region are permitted to occupy the same table, the same chamber, and — in the language of the Bureau — the "same asserted ground." The phase is administratively brief and procedurally interminable: of the 41,608 Syntheses recorded in the Synthesis Ledger during Cycle 12,891, the median Synthesis Phase occupied eleven days on the calendar and forty-nine years of accumulated chamber time.

Position in the Sequence

The Synthesis Phase follows the Isolation of Variance and the Comparative Synthesis procedure, taking as its input the variance schedules those procedures produce. It is commonly confused with the Integration Phase, which follows Doctrinal Integration and is concerned with the reconciliation of doctrine rather than ground. The distinction is set out in Clause 9.02 of the Twelfth Concordance, which states that "the Integration Phase shall not be commenced while any point of ground remains asserted twice," a prohibition the Bureau of Cartographic Standards has read narrowly since Cycle 12,887 and which the Chamber of Cartographic Synthesis has read broadly since its founding.

The phase is not to be confused with the Phase Delta: Verdict, despite the persistent habit among junior clerks of the Validation Amp Synthesis Office of filing Verdict tallies in the Synthesis docket. That error is corrected at Audit, but not before it has been corrected twice.

Procedure in the Chamber

Synthesis is conducted in a sealed chamber on a table of certified neutrality, under the supervision of a Presiding Synthesist and two witnesses drawn from the referencing floors. Each map is unrolled flat and weighted at the corners with standard brass plummets. The Synthesist then asserts ground: that is, for each disputed point, the Synthesist declares which map's account of that point shall be treated as the ground of the floor, and the losing account is transcribed onto the reverse of the founding map in the hand of the junior witness. Ground that can be asserted in neither direction is marked with a single vertical stroke in red and set aside for the Stillness Phase.

The procedure is known for its length. The Synthesis Phase of the Phase 2 reconciliation, which concerned three mutually contradictory surveys of a single infirmary corridor on Floor 208, was declared open in Cycle 12,764 and closed in Cycle 12,889, having in that time consumed four Presiding Synthesists. Its closing entry in the Ledger reads simply: "Ground asserted. Corridor narrowed by eleven inches. Noted."

A visiting rule, posted at the chamber door and reaffirmed by the Bureau in every cycle since 12,802: no one may enter the Synthesis Phase barefoot, and no map may be unrolled with a cat in the chamber.

The Increment Recension and the Grievance of Clerk Venn

The governing text of the phase is the Increment Recension of the Twelfth Concordance, promulgated in Cycle 12,886, which holds that the Synthesis Phase advances only in increments of asserted ground and that no increment may be opened before the preceding increment is sealed by the Presiding Synthesist in the presence of both witnesses. For a century the Recension was understood to mean that increments could not be worked in parallel, and chambers were accordingly locked to a single mode of comparison.

Clerk Armund Venn, second witness to the Synthesis Phase of the old East Stairwell surveys, dissented. Venn had observed that the seal on an increment does not describe the increment's content but only its closure, and that a sealed increment could therefore be worked again from the beginning without disturbing the seal. He filed his reading in a memorandum of forty-one leaves, and the memorandum was refused registration on the ground that the Synthesis Phase was open and no new arguments might be admitted to a chamber during an open phase. Venn's reading was never formally rejected. It was simply never admitted, which he noted, in the margin of the ninth leaf, was a different thing. Venn left the Bureau in Cycle 12,878 and is not recorded again in the Ledger.

Doctrinal Dispute

There is no settled position on whether the Synthesis Phase may be opened before the Isolation of Variance has been certified. Clause 17.04 of the Twelfth Concordance, which governs Lumen Synthesis and extends spatial synthesis principles to dimensional energy, treats certification as a condition of entering the phase at all. The Seventh, by contrast, lists certification among the acts that may be performed "during or after" the open phase, and the Bureau has cited the Seventh when pressed. The Validation Amp Synthesis Office has declined to offer a view, on the ground that its remit under the Seventh Concordance is confined to declared overflow during verification and that variance certification is a matter for the Bureau of Cartographic Standards.

Where the two documents conflict, chambers have in practice proceeded and the question has been referred to the Concordance Reconciliation Docket, where it has sat since Cycle 12,844. The docket's most recent minute observes that the matter will likely resolve itself. No one has recorded how.

Record and Closure

Every asserted ground is entered in the Synthesis Ledger on Floor 441 at the moment of assertion, in the hand of the Presiding Synthesist and no other. The Ledger is non-linear and is read by torchlight, and the phase is considered closed only when the final increment has been sealed and the Ledger entry has been initialled by both witnesses and the Presiding Synthesist. Where a witness has died before initialling, a Post-Incident Review is convened and the phase is closed in absentia, with the deceased witness's mark supplied by the Registrar of Ledgers in red ink, a practice the Bureau regards as settled and the witnesses' guilds have contested in every cycle since 12,851.