A note on the isotopy problem for $$ mathbb{R}^2 $$-planes

For a class of stable planes we define a notion of isotopy equivalence withrespect to that class and prove that any two planes of a certain class of -planes comprising all affine -planes are isotopy equivalent. Furthermore we obtain that all affine -planes are isotopy equivalent in the class of affine -planes. Finally we give an example which shows that this approach cannot be easily generalizedto 2-dimensional projective planes, and we outline a different way for apossible generalization.Received: 27 April 2001