3 problems

Let $L$ be a relational language with finitely many unary relations and infinitely many relations of some arity $a\geq 2$. Let $\str H$ be a countable unrestricted $L$-structure re…

Let $\str H$ and $\str G$ be the structures in the source, let $\varphi\colon\str H\to\str G$ be an embedding, and let an envelope of a finite subset have the source's valuation-tr…

Let $\mathcal{K}$ be a relational Fraïssé class with finitely many relations and a finite constraint set. A constraint set is a finite set of finite structures such that membership…