View source for Asymmetric variety

An oriented variety <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013580/a0135801.png" /> without an orientation-reversing homeomorphism. Thus, for instance, the complex projective plane is an asymmetric variety, since the self-intersection of the complex straight line is <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013580/a0135802.png" /> or <img align="absmiddle" border="0" src="https://www.encyclopediaofmath.org/legacyimages/a/a013/a013580/a0135803.png" />, depending on the orientation. Certain knots can differ from their mirror image owing to the fact that their branched coverings are asymmetric varieties.



====Comments====
This notion can be found, e.g., in [[#References|[a1]]], Chapt. 5.

====References====
<table><TR><TD valign="top">[a1]</TD> <TD valign="top">  M.W. Hirsch,   "Differential topology" , Springer  (1976)</TD></TR></table>