Cancellation law of congruence and gcd.
14693
$d = \gcd(c,m),\ ac≡bc\pmod{\! m}\Rightarrow a≡b\pmod {\!m/d}\ $ [Congruence Cancellation & Division Rule]
83871
GCDs in integral domains are unique up to unit factors (associates)
157508
prove $lcm(a,gcd(b,c))=gcd(lcm(a,b),lcm(a,c))$
136756
Computational check whether $G\cong \tilde G$
102133
Prove: $\gcd(a,b) = \gcd(a, b + at)$.
8160
What is $\gcd(0,a)$, where $a$ is a positive integer?
8481
System of congruence relations
94914
Concise proof that every common divisor divides GCD without Bezout's identity?
77064
Proving $\gcd((a+b)^m,(a-b)^m)\le2^m$ for coprime $a,b$ and $m \in \Bbb N$
110313
Prove that $\gcd(f(x),g(x)) = 1$.
61825
Congruence class $[a]$ modulo $m$, $\gcd(x, m) = \gcd(a, m)$
107914
Expanding GCDs Reasoning: $\gcd(a,c) \cdot \gcd(b,c) = \gcd(ab,bc,ac,cc)$
78031
$c\mid a,b\iff c\mid\gcd(a,b)$ [GCD Universal Property]
38547
Why does the Euclidean algorithm for finding GCD work?
60596
Euclidean Algorithm for GCD of polynomials
84501
Proof involving Cyclic group, generator and GCD
58267
Godel's pairing function and proving c = c*c for aleph cardinals