Extension of Positive Operators.

The main result states that if E is a separable Fréchet lattice and F is a (locally solid) topological vector lattice with the σ-interpolation property then each positive linear operator T0 from a majorizing subspace G ⊂ E into F admits extension to a continuous positive linear operator T from E into F. This fact is proved by using only the axiom of countable choice. [ABSTRACT FROM AUTHOR]