Abstract. A formula ψ(Y ) is a selector for a formula ϕ(Y ) in a structure M if there exists a unique Y that satisfies ψ in M and this Y also satisfies ϕ. A formula ψ(X, Y )...
For a two-variable formula (X, Y ) of Monadic Logic of Order (MLO) the Church Synthesis Problem concerns the existence and construction of an operator Y = F(X) such that (X, F(X)) ...