Abstract:
It is shown that the set of all $C$-compact orthogonally additive operators from a vector lattice $E$ to an $AM$-space $F$ is a vector lattice and the lattice operations can be calculated by the Riesz–Kantorovich formulas. Moreover, a positive $AM$-compact orthogonally additive map defined on a lateral ideal of a vector lattice $E$ and taking values in an $AM$-space $F$ can be extended to the whole space $E$.