Final answer:
A 'ring' (R, +, ·) is a set R along with two binary operations + and · that satisfy specific properties including associativity, existence of identities, existence of inverses, commutativity, and distributivity.
Step-by-step explanation:
A 'ring' (R, +, ·) consists of a set R along with two binary operations + and · (called 'addition' and 'multiplication'), satisfying the following properties:
- Associativity for addition: ∀a, b, c ∈ R (a + b) + c = a + (b + c)
- Existence of additive identity: ∃0R ∈ R ∀a ∈ R a + 0R = 0R + a = a
- Existence of additive inverses: ∀a ∈ R ∃z ∈ R a + z = z + a = 0R
- Commutativity for addition: ∀a, b ∈ R a + b = b + a
- Associativity for multiplication: ∀a, b, c ∈ R (a · b) · c = a · (b · c)
- Existence of multiplicative identity: ∃1R ∈ R ∀a ∈ R a · 1R = 1R · a = a
- Distributivity: ∀a, b, c ∈ R a · (b + c) = a · b + a · c (a + b) · c = a · c + b · c