The underlying set of the fundamental group of 
is the set of based homotopy
classes from the circle to 
, denoted ![[S^1,X]](/images/equations/Co-H-Space/Inline3.svg)
. For general spaces 
and 
,
there is no natural group structure on ![[X,Y]](/images/equations/Co-H-Space/Inline6.svg)
, but when there is a natural group structure, 
is called a co-
-space.
Co-H-Space
See also
Co-H-Group, Fundamental Group, H-Space, Homotopy ClassExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Co-H-Space." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Co-H-Space.html