Coherent Conditions: Algebraic Geometry for Arbitrary Classes of Algebras

Universal algebraic geometry is generalised from solutions of equations in a single algebra to the study of $\varphi$- or $K$-spectra, akin to the prime spectrum of a ring. We explore their basic properties and constructions, give a correspondence between certain quantifier-free propositions and closed sets in the Zariski topology of a free algebra, and show the connection with current UAG. Lastly, equationally Noetherian classes and irreducible spectra are explored.