Hurwitz theorem of congruence

pi theorem|π theorem

congruence relations on congruence lattice

Buckingham theorem， pi theorem

Kolgomorov-Arnol‘d-Moser theorem， KAM theorem

πtheorem π pi theorem

(Weakly) covering congruence

∨-congruence

0-bisimple congruence

algebraic congruence

axiom of congruence

axioms of congruence

bi-semiring congruence

canonical congruence

characterized invariant congruence

class of a congruence

Clifford congruence

coefficient of congruence

complete congruence