## Mathematics Subject Classification – MSC2020

Groups and semigroups of linear operators [See also 20M20] {For nonlinear operators, see 47H20} 4728

Nonlinear operators and their properties {For global and geometric aspects, see 49J53, 58-XX, especially 58Cxx} 33737

Equations and inequalities involving nonlinear operators [See also 46Txx] {For global and geometric aspects, see 58-XX} 21256