Explore related knowledge and questions →

Question 15173: Find a Two-Sided Inverse of the Specified Nonzero Element

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 76

← Question derivation index · Original question batch

R0029-15173 · q-20261014-advance-20261030-r01-finite-field-0048

Original question and givens

Use the same already qualified complete finite commutative unital-ring tables on Fin(5)={0,…,4}, addition=[[0, 1, 2, 3, 4], [1, 4, 3, 0, 2], [2, 3, 1, 4, 0], [3, 0, 4, 2, 1], [4, 2, 0, 1, 3]] and multiplication=[[0, 0, 0, 0, 0], [0, 2, 3, 4, 1], [0, 3, 4, 1, 2], [0, 4, 1, 2, 3], [0, 1, 2, 3, 4]] in carrier-label order. The actual zero and one are distinct and need not be labels 0 and 1. The inverse audit is additional to, not a replacement for, those ring axioms. Division by zero is never defined. A finite field has prime-power order, not necessarily prime order. element=1 is nonzero. Give (element,one,inverse,found?).

  • G001 — Use the same already qualified complete finite commutative unital-ring tables on Fin(5)={0,…,4}, addition=[[0, 1, 2, 3, 4], [1, 4, 3, 0, 2], [2, 3, 1, 4, 0], [3, 0, 4, 2, 1], [4, 2, 0, 1, 3]] and multiplication=[[0, 0, 0, 0, 0], [0, 2, 3, 4, 1], [0, 3, 4, 1, 2], [0, 4, 1, 2, 3], [0, 1, 2, 3, 4]] in carrier-label order. The actual zero and one are distinct and need not be labels 0 and 1. The inverse audit is additional to, not a replacement for, those ring axioms. Division by zero is never defined. A finite field has prime-power order, not necessarily prime order. element=1 is nonzero. Give (element,one,inverse,found?).

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

same complete carrier Fin(5);addition=[[0, 1, 2, 3, 4], [1, 4, 3, 0, 2], [2, 3, 1, 4, 0], [3, 0, 4, 2, 1], [4, 2, 0, 1, 3]];multiplication=[[0, 0, 0, 0, 0], [0, 2, 3, 4, 1], [0, 3, 4, 1, 2], [0, 4, 1, 2, 3], [0, 1, 2, 3, 4]]

After

actual zero=0;one=4;additive inverses=[0, 3, 4, 1, 2];additive commute/associate=[Yes, Yes];multiplicative commute/associate=[Yes, Yes];left/right distributive=[Yes, Yes]

Conditions: none

Even where the raw inverse oracle has looser guards,independently qualify the complete commutative unital parent declared by the source English scope,including every additive/distributive axiom and distinct identities.Do not skip them by name or inverse search alone.

Step identifiers and dependencies

Rule: field_stated_full_commutative_parent_not_raw_oracle_shortcut · Uses: G001

S002 · implies

Before

element label=0;actual zero=0;one=4;two-sided multiplicative inverse candidates=[]

After

selected inverse witness=null;nonzero inverse obligation=No

Conditions: none

Search the whole carrier for both products equaling the actual one.Nonzero is judged against the actual zero,not label0;zero has no inverse obligation.

Step identifiers and dependencies

Rule: field_all_nonzero_inverse_obligations_actual_labels · Uses: G001, S001

S003 · implies

Before

element label=1;actual zero=0;one=4;two-sided multiplicative inverse candidates=[3]

After

selected inverse witness=3;nonzero inverse obligation=Yes

Conditions: none

Search the whole carrier for both products equaling the actual one.Nonzero is judged against the actual zero,not label0;zero has no inverse obligation.

Step identifiers and dependencies

Rule: field_all_nonzero_inverse_obligations_actual_labels · Uses: G001, S002

S004 · implies

Before

element label=2;actual zero=0;one=4;two-sided multiplicative inverse candidates=[2]

After

selected inverse witness=2;nonzero inverse obligation=Yes

Conditions: none

Search the whole carrier for both products equaling the actual one.Nonzero is judged against the actual zero,not label0;zero has no inverse obligation.

Step identifiers and dependencies

Rule: field_all_nonzero_inverse_obligations_actual_labels · Uses: G001, S003

S005 · implies

Before

element label=3;actual zero=0;one=4;two-sided multiplicative inverse candidates=[1]

After

selected inverse witness=1;nonzero inverse obligation=Yes

Conditions: none

Search the whole carrier for both products equaling the actual one.Nonzero is judged against the actual zero,not label0;zero has no inverse obligation.

Step identifiers and dependencies

Rule: field_all_nonzero_inverse_obligations_actual_labels · Uses: G001, S004

S006 · implies

Before

element label=4;actual zero=0;one=4;two-sided multiplicative inverse candidates=[4]

After

selected inverse witness=4;nonzero inverse obligation=Yes

Conditions: none

Search the whole carrier for both products equaling the actual one.Nonzero is judged against the actual zero,not label0;zero has no inverse obligation.

Step identifiers and dependencies

Rule: field_all_nonzero_inverse_obligations_actual_labels · Uses: G001, S005

S007 · implies

Before

qualified field;selected nonzero element=1;actual one=4

After

inverse=3;left product=4;right product=4

Conditions: none

Existence follows from full field qualification;read back both products to one.The frozen inverse/division families contain no undefined output.Do not fabricate null for a missing inverse or invert zero.

Step identifiers and dependencies

Rule: selected_nonzero_field_inverse_not_zero_division · Uses: G001, S006

Reverse checks

  • S007 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S006 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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

(1, 4, 3, Yes)

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: dd29c7e5d9f459fcce6d278347c6d2bfbcd7e181f87e5217512555f78d9d185b
  • candidate record SHA-256: c48c857bf59c997102bfe981bbcfcec7003bf9b8f804050e19d9f738038315b7
  • semantic review receipt SHA-256: 8c0ef6ca8c5ba2754e41f30c2b32bcb757756152d97421f7396d39038c11f725
  • question-first witness SHA-256: c7920a0ff8e724b7e566ebbda30b31d8087c136974b62f8c760fbd26ab816117
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON