A transformation function that smooths out discontinuous functions into their continuous counterparts. Moreau envelopeThe Moreau envelope (or the Moreau-Yosida regularization) M f {\displaystyle M_{f}} of a proper lower semi-continuous convex function f {\displaystyle f} is a smoothed version of f {\displaystyle f} . It was proposed by Jean-Jacques Moreau in 1965.https://en.wikipedia.org/wiki/Moreau_envelope