[1] : The Free On-line Dictionary of Computing (27 SEP 03)

liskov substitution principle
     
         lsp the principle that
        object-oriented functions that use pointers or
        references to a base class must be able to use objects of
        a derived class without knowing it.
     
        barbara liskov first wrote it as follows: if for each object
        o1 of type s there is an object o2 of type t such that for all
        programs p defined in terms of t, the behaviour of p is
        unchanged when o1 is substituted for o2 then s is a subtype
        of t.
     
        a function that violates the lsp uses a reference to a base
        class and must know about all the derivatives of that base
        class.  such a function violates the open/closed principle
        because it must be modified whenever a new derivative of the
        base class is created.
     
        liskov, b. data abstraction and hierarchy, sigplan
        notices. 235, may 1988.
     
        2001-09-14
     
     
see also:
object-oriented functions pointers base class objects derived class 
subtype open/closed principle 

Substitution >> S Words
Substitution, definition of term: Substitution
substitution_pag1.html

Principle >> P Words
Principle, definition of term: Principle
principle_pag1.html

Vital Principle >> V Words
Vital Principle, definition of term: Vital Principle
vital+principle_pag1.html

Kiss Principle >> K Words
Kiss Principle, definition of term: Kiss Principle
kiss+principle_pag1.html