Every thing X also has a parent P , which indicates a larger class to which every instance x of X belongs. We also say that X is a subclass of P. For example, the mathematical notion of a module P and a submodule X may be modelled this way. The parent of x can be obtained with the function parent.
i1 = parent 2
o1 = Nothing
o1 : Type
Nothing -- the empty class.
i2 = parent parent 2
o2 = Thing
o2 : Type
Thing -- the class of all things.
i3 = parent parent parent 2
o3 = Thing
o3 : Type
Thing -- the class of all things.
i4 = class 2
o4 = ZZ
o4 : Ring
ZZ -- denotes the class of all integers.
i5 = parent class 2
o5 = Thing
o5 : Type
Thing -- the class of all things.
i6 = parent parent class 2
o6 = Thing
o6 : Type
Thing -- the class of all things.
i7 = class class 2
o7 = Ring
o7 : Type
Ring -- the class of all rings.
i8 = parent class class 2
o8 = Type
o8 : Type
Type -- the class of all types.
i9 = parent parent class class 2
o9 = MutableHashTable
o9 : Type
MutableHashTable -- the class of all mutable hash tables.
i10 = parent parent parent class class 2
o10 = HashTable
o10 : Type
HashTable -- the class of all hash tables.
i11 = parent parent parent parent class class 2
o11 = Thing
o11 : Type
Thing -- the class of all things.
The classes and parents provide a uniform way for operations on things to locate the appropriate functions needed to perform them. Please see using methods and binary method now for a brief discussion.
For more details, see one of the topics below.
For related topics, see one of the following.
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