Abstracting a formal model reveals a natural internal structure and so a structure for a design. The models are used to validate requirements, specifications, designs, algorithms, data structures, and data bases. . Example - A University . Each course is offered by one dept. Each qualification belongs to a department.
Students are people.
Propositions A proposition can have two possible meanings - true and false. Unlike most programming languages mathematics has two kinds of infix operator. Predicates and Quantifiers A predicate can have variables, quantifiers and equalities as well the propositions listed above. The syntax attempts to make the writing of formal statements as natural as possible. It is therefore unambiguous to use sets to declare the type of a variable.