Minimum Norm Extremals in Function Spaces : With Applications to Classical and Modern Analysis Nonlinear minimization problems Minimization with linear operators Nonlinear operators in LP 1<p L Minimization problems for elliptic operators L1 minimization in one and several variables Sets of uniqueness in L minimization problems Bang Bang optimal controls A general theorem of Kuhn Tucker type Stable and unstable elastica equilibrium and the problem of minimum curvature Approximation by extremals of nonlinear differential expressions in one variable and quadratic forms in several variables The trigonometric and algebraic favard problem Minimization and interpolation at integer points of the real axis The Landau problem and Kolmogorov’s theorem Perfect interpolating splines on compact intervals A pólya algorithm for the favard solution N width characterizations and Whitney type theorems Application of the Riesz Fredholm Schauder theory to spline functions Epilogue.