Inheritence

• Inheritence is now used by Object Oriented Programming
• The idea of Is-A is that the subcategory is a specialisation of the super-category. So an Ostrich Is-A bird, and is thus a special type of bird.
• Properties are also inherited; so a bird is covered by feathers and therefore an Ostrich is covered by feathers.
• This property inheritence can also be explicitly overriden.
• So, a bird travels by flying, but an Ostrich travels by Walking
• Of course things can inherit from multiple super-categories. Dogs are pets, and are mammals.
• Inheritence Conflicts. This means that there can be conflicts.
• Instances are a special subset of inheritence. (Type vs. Token)
• They refer to a particular individual, where the general node refers to a class.
• Inheritence and instance-of gives representational economy.
• Another popular arc is part-of.