If 
is analytic
on a domain 
, then a point 
on the boundary 
is called regular if 
extends to be an analytic
function on an open set containing 
and also the point 
(Krantz 1999, p. 119).
Regular Point
See also
Ordinary PointExplore with Wolfram|Alpha
References
Krantz, S. G. Handbook of Complex Variables. Boston, MA: Birkhäuser, p. 119, 1999.Referenced on Wolfram|Alpha
Regular PointCite this as:
Weisstein, Eric W. "Regular Point." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RegularPoint.html