Let X be a set, (R, +, \cdot) be a ring and let f:X\mapsto R be a function. A zero of a function f is a point \alpha\in X such that f(\alpha)=0, where 0\in R denotes the zero element of the ring R. A zero of a function is sometimes called a root of the function.
Chapters: 1 2
Corollaries: 3
Definitions: 4
Proofs: 5 6 7
Propositions: 8 9 10
Theorems: 11 12
