Ringoid
A ringoid 
is a set 
with two binary operators, conventionally denoted addition (
) and multiplication (
),where distributes over left and right:
A ringoid can be empty.See also Binary Operator, Ring, Semiring
References
Rosenfeld, A. An Introduction to Algebraic Structures. New York: Holden-Day, 1968.
- Eccentric
- Eccentric Angle
- Eccentric Anomaly
- Eccentricity
- Eccentricity (Graph)
- Echidnahedron
- Eckardt Point
- Eckert IV Projection
- Eckert VI Projection
- Economized Rational Approximation
- Eddington Number
- Edge-Coloring
- Edge Connectivity
- Edge (Graph)
- Edge Number
- Edge (Polygon)
- Edge (Polyhedron)
- Edge (Polytope)
- Edgeworth Series
- e-Divisor
- Edmonds' Map
- Efron's Dice
- Egg
- Egyptian Fraction
- Ehrhart Polynomial