GEOMANCY — CALCULATION DIAGNOSIS EXERCISE · 7 November 2026
Existing fictional case; local convention geo-shield-top-v1. No new draw. Internal review, not independent validation of the traditions.

EXERCISE — WITHOUT CONSULTING THE MODEL ANSWER
The sixteen numbers are: 15, 15, 16, 14, 15, 16, 15, 14, 12, 6, 9, 7, 10, 11, 10, 10.
Form four mothers from successive groups of four numbers, from top to bottom; odd=1, even=2. Transpose the mothers to obtain the daughters. Combine line by line: equal values give2, different ones give1.
1. Note the fifteen codes and their parents before looking at the judge.
2. Three copies are below. Find the first divergence in each and explain the faulty step. Their judge has an even number of single-point lines. Is that enough to accept them?
lignes_inversees: 2211 / 2121 / 1122 / 2212 / 2212 / 2112 / 1221 / 1122 / 2112 / 1112 / 2122 / 2121 / 1222 / 2221 / 1221
meres_inversees: 2122 / 2211 / 1212 / 1122 / 2211 / 1221 / 2112 / 2122 / 2111 / 2112 / 1212 / 2212 / 2221 / 1222 / 1221
filles_copiees: 1122 / 1212 / 2211 / 2122 / 1122 / 1212 / 2211 / 2122 / 2112 / 2111 / 2112 / 2111 / 2221 / 2221 / 2222
3. Replace each initial number with itself+2. Should a different shield chart be obtained? Can it be inferred from this that the numbers of the tracing are authentic?
4. A person changes the numbers AND recalculates all the figures without error. Can the consistency check prove that these numbers come from the stated tracing?

MODEL ANSWER — FIFTEEN POSITIONS
1. 1122; origin: entries1–4
2. 1212; origin: entries5–8
3. 2211; origin: entries9–12
4. 2122; origin: entries13–16
5. 1122; origin: line1 of mothers1–4
6. 1221; origin: line2 of mothers1–4
7. 2112; origin: line3 of mothers1–4
8. 2212; origin: line4 of mothers1–4
9. 2112; origin: 1+2
10. 2111; origin: 3+4
11. 2121; origin: 5+6
12. 2122; origin: 7+8
13. 2221; origin: 9+10
14. 2221; origin: 11+12
15. 2222; origin: 13+14

MODEL ANSWER — DIAGNOSIS OF THE COPIES
lignes_inversees: divergences at positions 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 15; judge 1221, even parity=true; restore refused=true. Figure 1 inconsistent with the points: restore refused.
meres_inversees: divergences at positions 1, 2, 3, 4, 5, 8, 9, 10, 11, 12, 14, 15; judge 1221, even parity=true; restore refused=true. Figure 1 inconsistent with the points: restore refused.
filles_copiees: divergences at positions 6, 7, 8, 11, 12; judge 2222, even parity=true; restore refused=true. Figure 6 inconsistent with the points: restore refused.
Reversed lines: each mother is read from bottom to top; restore the declared order before the transposition. Reversed mothers: the groups are in reverse order; restore their order of entry. Copied daughters: they repeat the mothers instead of each taking one line from the four mothers.
The even judge is a necessary check of this construction, not sufficient proof that the data and each parent have been respected. A copy may even keep the same judge while differing elsewhere: consult the codes and divergences above, without generalising these three examples to all errors.
Adding2 preserves the sixteen parities: the same shield chart is expected. This proves neither the authenticity nor the provenance of the tracing. Modified numbers with a consistent calculation may be accepted by the parser: structural integrity and origin are two distinct questions.

EXAMPLE ASSESSMENT
Observation: I compare the fifteen codes, not just the last one. Hypothesis: one copy has reversed the mothers. Optional trial: take the groups again in their order and compare the first divergence. Criterion: the fifteen codes and parents match the model answer. Possible assessment: not tried, error corrected, or convention still undecidable; no future event inferred.

EVIDENCE AND LIMITS
XOR oracle separate from the engine, targeted comparison on the existing case and its mutations; this is not an independent professional implementation nor a new review of the historical sources. The names of the figures are not validated by this oracle. No paper trial, device trial, real download, prediction, professional review or client benefit demonstrated. No personal data to enter. The other functions and historical files remain preserved.