Use the complete finite self-map on Fin(9)={0,…,8}, T(x)=(a*x+b) mod 9, a=-3, b=-1. Take least nonnegative residues even for negative a*x+b. Fixed points, return times and least positive periods are different notions; the conclusion concerns this finite model only. x=4. Give (modulus,a,b,x,T(x),T(x)=x?).
G001 — Use the complete finite self-map on Fin(9)={0,…,8}, T(x)=(a*x+b) mod 9, a=-3, b=-1. Take least nonnegative residues even for negative a*x+b. Fixed points, return times and least positive periods are different notions; the conclusion concerns this finite model only. x=4. Give (modulus,a,b,x,T(x),T(x)=x?).
Definition and scope
Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.
Check the transition using quotient and nonnegative remainder;n>0 and0≤remainder<n ensure uniqueness.
Step identifiers and dependencies
Rule: orbit_successor · Uses: G001, S003
S005 · implies
Before
T(4)=5
After
T(x)=x: No
Conditions: none
A fixed point returns in one step;this is equivalent to least positive period1,not merely a later return.
Step identifiers and dependencies
Rule: fixed_point_definition · Uses: G001, S004
Reverse checks
S005 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
S004 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
S003 · premise_and_result_audit — Recompute fixed audit affine value with exact rational arithmetic, not rounded decimals.
S002 · premise_and_result_audit — Recompute fixed audit product with exact rational arithmetic, not rounded decimals.
S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
Result
(9, -3, -1, 4, 5, No)
The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.
This question review and source binding
Review date: 2026-10-26
Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.