444 ;;Quote: an abstract data type is a class of objects defined by a representation-independent specification of its behavioral characteristics

445 ;;Quote: software is not fractal; high-level design is qualitatively different from low-level design; e.g., system architecture, abstract data type, and implementation

446 ;;Quote: a fixed set of type abstractions is not sufficient, need application-domain-specific types

447 ;;Quote: programs are complex systems that should be reliable and infinitely malleable; they should manage complexity and facilitate change

447+;;Quote: decomposition creates structure while abstraction suppresses detail; data abstraction decomposes a system into domain-specific types that remain relevant over the lifetime of a program

447 ;;Quote: the representation invariant of an abstract type defines its valid representations as the values of a data structure

447 ;;Quote: the abstraction function of an abstract type maps abstract values to values of its data structure

450 ;;Quote: data abstraction leads to programs as a collection of types, composing modules instead of individual procedures