Pointed set
From Wikipedia, the free encyclopedia
In mathematics, a pointed set is a set X with a distinguished basepoint x0 in X. Maps of pointed sets (based maps) are functions preserving basepoints, i.e. a map f : X → Y such that f(x0) = y0. This is usually denoted
- f : (X, x0) → (Y, y0).
Pointed sets may be regarded as a rather simple algebraic structure. In the sense of universal algebra, they are structures with a single nullary operation which picks out the basepoint.
