Institute of Mathematics and Informatics Bulgarian Academy of Sciences
Serdica Mathematical Journal, Vol. 25, No 1, (1999), 41p-46p
We introduce the helm topology in the plane. We show that
(assuming the helm local injectivity and the Euclidean continuity)
each mapping which is oriented at all points of a helm domain U is oriented at U.
∗Research supported by the grant No. GAUK 186/96 of Charles University.