On Lebesgue constants of local parabolic splines

Lebesgue constants (the norms of linear operators from C to C) are calculated exactly for local parabolic splines with an arbitrary arrangement of knots, which were constructed by the second author in 2005, and for N.P. Korneichuk’s local parabolic splines, which are exact on quadratic functions. Both constants are smaller than the constants for interpolating parabolic splines.