Date: Jan 20, 2013 3:31 AM
Subject: Re: What is pi_0?
20.1.2013 1:37, W. Dale Hall wrote:
> Kaba wrote:
>> In this page
>> there is the notation pi_0 in the topology section. What does it refer
>> to? I don't see how the homotopy groups could cover n = 0...
> Note that for two maps f,g : (S^0, *) --> (X,*) to b homotopic, there
> must be a path connecting the images f(+1) and g(+1) of the non-
> distinguished points in X. In short, the homotopy set of (X,*) is just
> the set of path-components of X. In general, pi_0(X,*) has a
> distinguished point consisting of the path-component of the point *.
Makes sense. Thanks.