Hermite–Hadamard type inequality n/a Hermite–Hadamard inequalities interval-valued functions nonlinear programming Hermite–Hadamard inequality Hermite–Hadamard–Fejér type inequality Riemann integral bic Book Industry Communication::K Economics, finance, business & management::KN Industry & industrial studies::KNT Media, information & communication industries::KNTX Information technology industries bic Book Industry Communication::U Computing & information technology::UY Computer science fractional integral operator multiple integral functional BVP nonlinear problems Banach lattices Euler–Lagrange equations Green function Hahn–Banach type theorems Hermite-Hadamard Fejér type inequality Hermite-Hadamard type inequality Hermite–Hadamard Fejér inequality Hermite–Hadamard Fejér type inequality Jordan’s inequality LR-χ-pre-invex interval-valued function Lagrange 1-form L’Hôpital’s rule of monotonicity Markov moment problem Markov moment problems abstract interpolative Reich-Rus-Ćirić-type contractions with a shrink map auxiliary functions b-metric space