Question 372: Keep Signed Bezout Coefficients and Verify the Integer Identity

Original question and givens

Use the original signed integer a=5 and modulus n=48≥2. Exact extended Euclid gives nonnegative g=gcd(a,n) and signed coefficients x,y satisfying a*x+n*y=g. An inverse exists exactly when g=1; normalize its representative to 0≤inverse<n. Uniqueness means one residue class modulo n, not a unique integer representative. This family excludes moduli 0 and 1 and does not use approximate division. Give (a,n,gcd,x,y,bezout_value,classification), retaining the coefficients returned by exact Euclidean steps on |a| and n, with the sign of a restored in x.

• G001 — Use the original signed integer a=5 and modulus n=48≥2. Exact extended Euclid gives nonnegative g=gcd(a,n) and signed coefficients x,y satisfying a*x+n*y=g. An inverse exists exactly when g=1; normalize its representative to 0≤inverse<n. Uniqueness means one residue class modulo n, not a unique integer representative. This family excludes moduli 0 and 1 and does not use approximate division. Give (a,n,gcd,x,y,bezout_value,classification), retaining the coefficients returned by exact Euclidean steps on |a| and n, with the sign of a restored in x.

Definition and scope

Run extended Euclid on |a| and n and restore the sign of a. The coefficients are one Bezout witness, not a unique pair.

• mko-modular-inverse

Step-by-step derivation

a=5; n=48≥2

compute gcd and a Bezout certificate before inversion

divide 5 by 48

5=0·48+5

divide 48 by 5

48=9·5+3

divide 5 by 3

5=1·3+2

divide 3 by 2

3=1·2+1

divide 2 by 1

2=2·1+0

a·x := mul(5, -19)

a·x = -95

n·y := mul(48, 2)

n·y = 96

Bezout value := sum(-95, 96)

Bezout value = 1

5·(-19)+48·(2)=1

inverse representative=29; 5·29≡1 (mod 48)

Reverse checks

• S010 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S009 · premise_and_result_audit — Recompute Bezout value with exact rational arithmetic, not rounded decimals.
• S008 · premise_and_result_audit — Recompute n·y with exact rational arithmetic, not rounded decimals.
• S007 · premise_and_result_audit — Recompute a·x with exact rational arithmetic, not rounded decimals.
• S006 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S005 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S004 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S003 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S002 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.
• S001 · premise_and_result_audit — Check integer identities, remainder bounds and gcd conditions; congruence is not integer equality.

Result

(5, 48, 1, -19, 2, 1, Bezout_equals_one)

The full substitutions and premise audits recover the original answer, retaining its field order and verdict meanings.

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.