We prove that the formulae of the conjugates of
the precomposition with a linear operator, of the sum of finitely many functions and of the sum between a function and the precomposition of another one with a linear operator hold even when the convexity assumptions are replaced by almost convexity or nearly convexity. We also show that the duality statements due to Fenchel hold when the functions involved are taken only almost convex, respectively nearly convex.
Keywords:
Fenchel duality, conjugate functions, almost convex
functions, nearly convex functions