2.3 Structures
In first order logic, formulas do not have meaning by themselves, and meaning is provided by specifying a structure in which the symbols of the language are interpreted as actual objects, functions, and relations. Structures A structure consists of a domain together with interpretations of all symbols in the signature, and it serves as the semantic environment in which formulas are evaluated. Definition 2.19 (Structure) A structure $\mathcal{M}$ for a...