# Ord – ordered types

The `Ord` class requires any type that wants to be an instance of it to first be an instance of the `Eq` class by using a **class constraint**, and additionally, to support the following methods:

```haskell
class (Eq a) => Ord a where
  (<), (<=), (>), (>=) :: a -> a -> Bool
  min, max :: a -> a -> a
```

In other words, the `Ord` class extends the `Eq` class and supports additional methods `(<)`, `(<=)`, `(>)`, `(>=)`, `min` and `max`. The `min` and `max` methods are defined by default as:

```haskell
min x y
 | x <= y = x
 | otherwise = y
 
max x y
 | x <= y = y
 | otherwise = x
```

And for a minimal definition of the class, we just need to define the `(<=)` method because the other ones also have default definitions:

```haskell
class (Eq a) => Ord a where
  (<), (<=), (>), (>=) :: a -> a -> Bool
  min, max :: a -> a -> a

    -- Minimal complete definition:
    -- (<=)
    
  x < y = x <= y && x /= y
  x > y = y < x
  x >= y = y <= x
  
  min x y
    | x <= y = x
    | otherwise = y
  max x y
   | x <= y = y
   | otherwise = x
```

All the basic types of Haskell are also instances of the `Ord` class.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://haskell.hpmeducation.com/type-classes/basic-classes/ord-ordered-types.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.