Section 27
Algebraic structures
Group
advanced
Algebraic structure with a group-invertible operation.
Abelian group
advanced
Group whose operation is also commutative.
Subgroup criterion
advanced
Compact criterion for verifying nonempty subgroups.
Ring
advanced
Structure with abelian-group addition and distributive multiplication.
Field
advanced
Commutative ring in which every nonzero element is invertible.
Prime finite field
advancedviz
Fundamental finite field in cryptography and coding theory.
Homomorphism
advanced
Map that preserves the algebraic operation.
Isomorphism
advanced
Bijective homomorphism; indicates structural equivalence.