structure (469B)
1 # Structure 2 3 A *structure* consists of a [domain] D, a [relational_signature] σ, and an interpretation giving, for each [relation] of σ of [arity_(relation)] k, a set of k-tuples that are those for which the relation holds 4 5 There may also be [function_symbols] 6 7 Operations: 8 9 - [product_(structures)] 10 - [disjoint_union] 11 - [substructure] 12 - [reduct]: restriction to a [subset] of the [signature] 13 14 Up: [logic] 15 16 See also: [relational_instance] 17 18 Aliases: structure (logic)