Explore related knowledge and questions →

Question 1559: A Fixed-Length Discrete Orbit Prefix

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

Return to catalogue page 8

← Question derivation index · Original question batch

R0002-01559 · q-20261013-advance-20261020-r01-discrete-dynamical-system-0034

Original question and givens

Use the complete finite self-map on Fin(8)={0,…,7} given by T(x)=(a*x+b) mod 8, a=9, b=17. Choose the least nonnegative residue, including for negative a*x+b. Time is discrete, indexed from 0; a finite orbit is not a general stability result. x0=0, updates=8. Give (modulus, a, b, x0, update count, orbit including x0). Zero updates gives the one-element prefix [x0].

  • G001 — Use the complete finite self-map on Fin(8)={0,…,7} given by T(x)=(a*x+b) mod 8, a=9, b=17. Choose the least nonnegative residue, including for negative a*x+b. Time is discrete, indexed from 0; a finite orbit is not a general stability result. x0=0, updates=8. Give (modulus, a, b, x0, update count, orbit including x0). Zero updates gives the one-element prefix [x0].

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.

Step-by-step derivation

S001 · implies

Before

X={0 through 7}; T(x)=(9x+(17)) mod 8

After

remainder representative always lies in X

Conditions: none

Fix the full finite state carrier and the same update rule;negative integers also use the standard remainder from0 through n−1.

Step identifiers and dependencies

Rule: finite_total_map · Uses: G001

S002 · implies

Before

x₀=0; transitions=8

After

initial orbit prefix=[0]

Conditions: none

Retain the initial state;steps=0 still has one known state,not an empty list.

Step identifiers and dependencies

Rule: orbit_initial_state · Uses: G001, S001

S003 · calculation

Before

transition1: a·x := mul(9, 0)

After

transition1: a·x = 0

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

transition1: a·x+b := sum(0, 17)

After

transition1: a·x+b = 17

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

reduce 17 modulo 8

After

17=2·8+1

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S004

S006 · calculation

Before

transition2: a·x := mul(9, 1)

After

transition2: a·x = 9

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

transition2: a·x+b := sum(9, 17)

After

transition2: a·x+b = 26

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

reduce 26 modulo 8

After

26=3·8+2

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S007

S009 · calculation

Before

transition3: a·x := mul(9, 2)

After

transition3: a·x = 18

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

transition3: a·x+b := sum(18, 17)

After

transition3: a·x+b = 35

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

reduce 35 modulo 8

After

35=4·8+3

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S010

S012 · calculation

Before

transition4: a·x := mul(9, 3)

After

transition4: a·x = 27

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

transition4: a·x+b := sum(27, 17)

After

transition4: a·x+b = 44

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · implies

Before

reduce 44 modulo 8

After

44=5·8+4

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S013

S015 · calculation

Before

transition5: a·x := mul(9, 4)

After

transition5: a·x = 36

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · calculation

Before

transition5: a·x+b := sum(36, 17)

After

transition5: a·x+b = 53

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · implies

Before

reduce 53 modulo 8

After

53=6·8+5

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S016

S018 · calculation

Before

transition6: a·x := mul(9, 5)

After

transition6: a·x = 45

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

transition6: a·x+b := sum(45, 17)

After

transition6: a·x+b = 62

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · implies

Before

reduce 62 modulo 8

After

62=7·8+6

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S019

S021 · calculation

Before

transition7: a·x := mul(9, 6)

After

transition7: a·x = 54

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S020

S022 · calculation

Before

transition7: a·x+b := sum(54, 17)

After

transition7: a·x+b = 71

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S021

S023 · implies

Before

reduce 71 modulo 8

After

71=8·8+7

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S022

S024 · calculation

Before

transition8: a·x := mul(9, 7)

After

transition8: a·x = 63

Conditions: none

Multiply the original coefficient by the current state;do not clip negative values to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S023

S025 · calculation

Before

transition8: a·x+b := sum(63, 17)

After

transition8: a·x+b = 80

Conditions: none

Add the same offset before reducing modulo n.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · implies

Before

reduce 80 modulo 8

After

80=10·8+0

Conditions: none

The integer identity together with0≤remainder<n determines the next state.

Step identifiers and dependencies

Rule: euclidean_remainder · Uses: G001, S025

S027 · implies

Before

computed transitions=8

After

orbit=[0, 1, 2, 3, 4, 5, 6, 7, 0]; number of entries=9

Conditions: none

Apply the same T to the preceding result; k transitions give k+1 states.

Step identifiers and dependencies

Rule: orbit_prefix_length · Uses: G001, S026

S028 · implies

Before

a finite requested prefix

After

no unrequested least-period claim

Conditions: none

This output is the requested prefix;it is not an unverified least-period proof from a few orbit values.

Step identifiers and dependencies

Rule: finite_prefix_scope · Uses: G001, S027

Reverse checks

  • S028 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S027 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S026 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S025 · premise_and_result_audit — Recompute transition8: a·x+b with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Recompute transition8: a·x with exact rational arithmetic, not rounded decimals.
  • S023 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S022 · premise_and_result_audit — Recompute transition7: a·x+b with exact rational arithmetic, not rounded decimals.
  • S021 · premise_and_result_audit — Recompute transition7: a·x with exact rational arithmetic, not rounded decimals.
  • S020 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S019 · premise_and_result_audit — Recompute transition6: a·x+b with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute transition6: a·x with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S016 · premise_and_result_audit — Recompute transition5: a·x+b with exact rational arithmetic, not rounded decimals.
  • S015 · premise_and_result_audit — Recompute transition5: a·x with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S013 · premise_and_result_audit — Recompute transition4: a·x+b with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute transition4: a·x with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Recompute transition3: a·x+b with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute transition3: a·x with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Recompute transition2: a·x+b with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute transition2: a·x with exact rational arithmetic, not rounded decimals.
  • 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 — Recompute transition1: a·x+b with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute transition1: a·x with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

(8, 9, 17, 0, 8, [0, 1, 2, 3, 4, 5, 6, 7, 0])

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.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: 0dfdfe94eab51a1a5555beed283bf31b7713f6a9b8c2c4ddd72d0814fc673fff
  • candidate record SHA-256: bc77b14b23481062fa90061f381a5b07536a1f72d18038c048114787352d38ab
  • semantic review receipt SHA-256: 340d74dcc6e37df6249594a0b79a9ee2af804337b7847478b3c1342af9722861
  • question-first witness SHA-256: 9a06233d190d31a16f13fb03b6c3ceba4cbb748fff6c997941f66ab1888dcca8
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON