diff --git a/README.md b/README.md
index 82e8b8a..f5ddd8e 100644
--- a/README.md
+++ b/README.md
@@ -18,42 +18,42 @@ This project provides:
 ## Type-class hierarchy
 
 <pre>
- <a href="#Setoid">Setoid</a>   <a href="#Semigroup">Semigroup</a>   <a href="#Foldable">Foldable</a>        <a href="#Functor">Functor</a>      <a href="#Contravariant">Contravariant</a>
-(<a href="#equals">equals</a>)   (<a href="#concat">concat</a>)   (<a href="#reduce">reduce</a>)         (<a href="#map">map</a>)        (<a href="#contramap">contramap</a>)
-    |         |           \         / | | | | \
-    |         |            \       /  | | | |  \
-    |         |             \     /   | | | |   \
-    |         |              \   /    | | | |    \
-    |         |               \ /     | | | |     \
-   <a href="#Ord">Ord</a>     <a href="#Monoid">Monoid</a>         <a href="#Traversable">Traversable</a> | | | |      \
-  (<a href="#lte">lte</a>)    (<a href="#empty">empty</a>)        (<a href="#traverse">traverse</a>)  / | | \       \
-                                     /  | |  \       \
-                                    /   / \   \       \
-                            <a href="#Profunctor">Profunctor</a> /   \ <a href="#Bifunctor">Bifunctor</a> \
-                             (<a href="#promap">promap</a>) /     \ (<a href="#bimap">bimap</a>)   \
-                                     /       \           \
-                                    /         \           \
-                                  <a href="#Alt">Alt</a>        <a href="#Apply">Apply</a>      <a href="#Extend">Extend</a>
-                                 (<a href="#alt">alt</a>)        (<a href="#ap">ap</a>)     (<a href="#extend">extend</a>)
-                                  /           / \           \
-                                 /           /   \           \
-                                /           /     \           \
-                               /           /       \           \
-                              /           /         \           \
-                            <a href="#Plus">Plus</a>    <a href="#Applicative">Applicative</a>    <a href="#Chain">Chain</a>      <a href="#Comonad">Comonad</a>
-                           (<a href="#zero">zero</a>)       (<a href="#of">of</a>)      (<a href="#chain">chain</a>)    (<a href="#extract">extract</a>)
-                              \         / \         / \
-                               \       /   \       /   \
-                                \     /     \     /     \
-                                 \   /       \   /       \
-                                  \ /         \ /         \
-                              <a href="#Alternative">Alternative</a>    <a href="#Monad">Monad</a>     <a href="#ChainRec">ChainRec</a>
-                                                      (<a href="#chainRec">chainRec</a>)
+ <a href="#Setoid">Setoid</a>   <a href="#Semigroupoid">Semigroupoid</a>  <a href="#Semigroup">Semigroup</a>   <a href="#Foldable">Foldable</a>        <a href="#Functor">Functor</a>      <a href="#Contravariant">Contravariant</a>
+(<a href="#equals">equals</a>)    (<a href="#compose">compose</a>)    (<a href="#concat">concat</a>)   (<a href="#reduce">reduce</a>)         (<a href="#map">map</a>)        (<a href="#contramap">contramap</a>)
+    |           |           |           \         / | | | | \
+    |           |           |            \       /  | | | |  \
+    |           |           |             \     /   | | | |   \
+    |           |           |              \   /    | | | |    \
+    |           |           |               \ /     | | | |     \
+   <a href="#Ord">Ord</a>      <a href="#Category">Category</a>     <a href="#Monoid">Monoid</a>         <a href="#Traversable">Traversable</a> | | | |      \
+  (<a href="#lte">lte</a>)       (<a href="#id">id</a>)       (<a href="#empty">empty</a>)        (<a href="#traverse">traverse</a>)  / | | \       \
+                                                   /  | |  \       \
+                                                  /   / \   \       \
+                                          <a href="#Profunctor">Profunctor</a> /   \ <a href="#Bifunctor">Bifunctor</a> \
+                                           (<a href="#promap">promap</a>) /     \ (<a href="#bimap">bimap</a>)   \
+                                                   /       \           \
+                                                  /         \           \
+                                                <a href="#Alt">Alt</a>        <a href="#Apply">Apply</a>      <a href="#Extend">Extend</a>
+                                               (<a href="#alt">alt</a>)        (<a href="#ap">ap</a>)     (<a href="#extend">extend</a>)
+                                                /           / \           \
+                                               /           /   \           \
+                                              /           /     \           \
+                                             /           /       \           \
+                                            /           /         \           \
+                                          <a href="#Plus">Plus</a>    <a href="#Applicative">Applicative</a>    <a href="#Chain">Chain</a>      <a href="#Comonad">Comonad</a>
+                                         (<a href="#zero">zero</a>)       (<a href="#of">of</a>)      (<a href="#chain">chain</a>)    (<a href="#extract">extract</a>)
+                                            \         / \         / \
+                                             \       /   \       /   \
+                                              \     /     \     /     \
+                                               \   /       \   /       \
+                                                \ /         \ /         \
+                                            <a href="#Alternative">Alternative</a>    <a href="#Monad">Monad</a>     <a href="#ChainRec">ChainRec</a>
+                                                                    (<a href="#chainRec">chainRec</a>)
 </pre>
 
 ## API
 
-<h4 name="TypeClass"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L128">TypeClass :: (String, Array TypeClass, a -> Boolean) -> TypeClass</a></code></h4>
+<h4 name="TypeClass"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L128">TypeClass :: (String, Array TypeClass, a -> Boolean) -> TypeClass</a></code></h4>
 
 The arguments are:
 
@@ -89,7 +89,7 @@ dependencies; `false` otherwise.
 to define parametrically polymorphic functions which verify their
 type-class constraints at run time.
 
-<h4 name="Setoid"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L253">Setoid :: TypeClass</a></code></h4>
+<h4 name="Setoid"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L253">Setoid :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Setoid][].
 
@@ -98,7 +98,7 @@ type-class constraints at run time.
 true
 ```
 
-<h4 name="Ord"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L263">Ord :: TypeClass</a></code></h4>
+<h4 name="Ord"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L263">Ord :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Ord][].
 
@@ -110,7 +110,31 @@ true
 false
 ```
 
-<h4 name="Semigroup"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L276">Semigroup :: TypeClass</a></code></h4>
+<h4 name="Semigroupoid"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L276">Semigroupoid :: TypeClass</a></code></h4>
+
+`TypeClass` value for [Semigroupoid][].
+
+```javascript
+> Semigroupoid.test(Math.sqrt)
+true
+
+> Semigroupoid.test(0)
+false
+```
+
+<h4 name="Category"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L289">Category :: TypeClass</a></code></h4>
+
+`TypeClass` value for [Category][].
+
+```javascript
+> Category.test(Math.sqrt)
+true
+
+> Category.test(0)
+false
+```
+
+<h4 name="Semigroup"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L302">Semigroup :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Semigroup][].
 
@@ -122,7 +146,7 @@ true
 false
 ```
 
-<h4 name="Monoid"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L289">Monoid :: TypeClass</a></code></h4>
+<h4 name="Monoid"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L315">Monoid :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Monoid][].
 
@@ -134,7 +158,7 @@ true
 false
 ```
 
-<h4 name="Functor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L302">Functor :: TypeClass</a></code></h4>
+<h4 name="Functor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L328">Functor :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Functor][].
 
@@ -146,7 +170,7 @@ true
 false
 ```
 
-<h4 name="Bifunctor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L315">Bifunctor :: TypeClass</a></code></h4>
+<h4 name="Bifunctor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L341">Bifunctor :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Bifunctor][].
 
@@ -158,7 +182,7 @@ true
 false
 ```
 
-<h4 name="Profunctor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L328">Profunctor :: TypeClass</a></code></h4>
+<h4 name="Profunctor"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L354">Profunctor :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Profunctor][].
 
@@ -170,7 +194,7 @@ true
 false
 ```
 
-<h4 name="Apply"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L341">Apply :: TypeClass</a></code></h4>
+<h4 name="Apply"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L367">Apply :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Apply][].
 
@@ -182,7 +206,7 @@ true
 false
 ```
 
-<h4 name="Applicative"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L354">Applicative :: TypeClass</a></code></h4>
+<h4 name="Applicative"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L380">Applicative :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Applicative][].
 
@@ -194,7 +218,7 @@ true
 false
 ```
 
-<h4 name="Chain"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L367">Chain :: TypeClass</a></code></h4>
+<h4 name="Chain"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L393">Chain :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Chain][].
 
@@ -206,7 +230,7 @@ true
 false
 ```
 
-<h4 name="ChainRec"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L380">ChainRec :: TypeClass</a></code></h4>
+<h4 name="ChainRec"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L406">ChainRec :: TypeClass</a></code></h4>
 
 `TypeClass` value for [ChainRec][].
 
@@ -218,7 +242,7 @@ true
 false
 ```
 
-<h4 name="Monad"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L393">Monad :: TypeClass</a></code></h4>
+<h4 name="Monad"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L419">Monad :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Monad][].
 
@@ -230,7 +254,7 @@ true
 false
 ```
 
-<h4 name="Alt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L406">Alt :: TypeClass</a></code></h4>
+<h4 name="Alt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L432">Alt :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Alt][].
 
@@ -242,7 +266,7 @@ true
 false
 ```
 
-<h4 name="Plus"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L419">Plus :: TypeClass</a></code></h4>
+<h4 name="Plus"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L445">Plus :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Plus][].
 
@@ -254,7 +278,7 @@ true
 false
 ```
 
-<h4 name="Alternative"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L432">Alternative :: TypeClass</a></code></h4>
+<h4 name="Alternative"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L458">Alternative :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Alternative][].
 
@@ -266,7 +290,7 @@ true
 false
 ```
 
-<h4 name="Foldable"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L445">Foldable :: TypeClass</a></code></h4>
+<h4 name="Foldable"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L471">Foldable :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Foldable][].
 
@@ -278,7 +302,7 @@ true
 false
 ```
 
-<h4 name="Traversable"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L458">Traversable :: TypeClass</a></code></h4>
+<h4 name="Traversable"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L484">Traversable :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Traversable][].
 
@@ -290,7 +314,7 @@ true
 false
 ```
 
-<h4 name="Extend"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L471">Extend :: TypeClass</a></code></h4>
+<h4 name="Extend"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L497">Extend :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Extend][].
 
@@ -302,7 +326,7 @@ true
 false
 ```
 
-<h4 name="Comonad"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L484">Comonad :: TypeClass</a></code></h4>
+<h4 name="Comonad"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L510">Comonad :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Comonad][].
 
@@ -314,7 +338,7 @@ true
 false
 ```
 
-<h4 name="Contravariant"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L497">Contravariant :: TypeClass</a></code></h4>
+<h4 name="Contravariant"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L523">Contravariant :: TypeClass</a></code></h4>
 
 `TypeClass` value for [Contravariant][].
 
@@ -326,7 +350,7 @@ true
 false
 ```
 
-<h4 name="toString"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1042">toString :: a -> String</a></code></h4>
+<h4 name="toString"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1081">toString :: a -> String</a></code></h4>
 
 Returns a useful string representation of its argument.
 
@@ -352,7 +376,7 @@ and Object.
 'Cons(1, Cons(2, Cons(3, Nil)))'
 ```
 
-<h4 name="equals"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1090">equals :: (a, b) -> Boolean</a></code></h4>
+<h4 name="equals"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1129">equals :: (a, b) -> Boolean</a></code></h4>
 
 Returns `true` if its arguments are of the same type and equal according
 to the type's [`fantasy-land/equals`][] method; `false` otherwise.
@@ -381,7 +405,7 @@ true
 false
 ```
 
-<h4 name="lt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1140">lt :: (a, b) -> Boolean</a></code></h4>
+<h4 name="lt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1179">lt :: (a, b) -> Boolean</a></code></h4>
 
 Returns `true` if its arguments are of the same type and the first is
 less than the second according to the type's [`fantasy-land/lte`][]
@@ -402,7 +426,7 @@ true
 false
 ```
 
-<h4 name="lte"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1164">lte :: (a, b) -> Boolean</a></code></h4>
+<h4 name="lte"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1203">lte :: (a, b) -> Boolean</a></code></h4>
 
 Returns `true` if its arguments are of the same type and the first
 is less than or equal to the second according to the type's
@@ -428,7 +452,7 @@ true
 false
 ```
 
-<h4 name="gt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1211">gt :: (a, b) -> Boolean</a></code></h4>
+<h4 name="gt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1250">gt :: (a, b) -> Boolean</a></code></h4>
 
 Returns `true` if its arguments are of the same type and the first is
 greater than the second according to the type's [`fantasy-land/lte`][]
@@ -449,7 +473,7 @@ false
 true
 ```
 
-<h4 name="gte"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1235">gte :: (a, b) -> Boolean</a></code></h4>
+<h4 name="gte"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1274">gte :: (a, b) -> Boolean</a></code></h4>
 
 Returns `true` if its arguments are of the same type and the first
 is greater than or equal to the second according to the type's
@@ -470,7 +494,31 @@ false
 true
 ```
 
-<h4 name="concat"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1259">concat :: Semigroup a => (a, a) -> a</a></code></h4>
+<h4 name="compose"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1298">compose :: Semigroupoid c => (c j k, c i j) -> c i k</a></code></h4>
+
+Function wrapper for [`fantasy-land/compose`][].
+
+`fantasy-land/compose` implementations are provided for the following
+built-in types: Function.
+
+```javascript
+> compose(Math.sqrt, x => x + 1)(99)
+10
+```
+
+<h4 name="id"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1313">id :: Category c => TypeRep c -> c</a></code></h4>
+
+Function wrapper for [`fantasy-land/id`][].
+
+`fantasy-land/id` implementations are provided for the following
+built-in types: Function.
+
+```javascript
+> id(Function)('foo')
+'foo'
+```
+
+<h4 name="concat"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1328">concat :: Semigroup a => (a, a) -> a</a></code></h4>
 
 Function wrapper for [`fantasy-land/concat`][].
 
@@ -491,7 +539,7 @@ built-in types: String, Array, and Object.
 Cons('foo', Cons('bar', Cons('baz', Cons('quux', Nil))))
 ```
 
-<h4 name="empty"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1283">empty :: Monoid m => TypeRep m -> m</a></code></h4>
+<h4 name="empty"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1352">empty :: Monoid m => TypeRep m -> m</a></code></h4>
 
 Function wrapper for [`fantasy-land/empty`][].
 
@@ -512,7 +560,7 @@ built-in types: String, Array, and Object.
 Nil
 ```
 
-<h4 name="map"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1307">map :: Functor f => (a -> b, f a) -> f b</a></code></h4>
+<h4 name="map"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1376">map :: Functor f => (a -> b, f a) -> f b</a></code></h4>
 
 Function wrapper for [`fantasy-land/map`][].
 
@@ -539,7 +587,7 @@ Nil
 Cons(1, Cons(2, Cons(3, Nil)))
 ```
 
-<h4 name="bimap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1337">bimap :: Bifunctor f => (a -> b, c -> d, f a c) -> f b d</a></code></h4>
+<h4 name="bimap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1406">bimap :: Bifunctor f => (a -> b, c -> d, f a c) -> f b d</a></code></h4>
 
 Function wrapper for [`fantasy-land/bimap`][].
 
@@ -548,7 +596,7 @@ Function wrapper for [`fantasy-land/bimap`][].
 Tuple('FOO', 8)
 ```
 
-<h4 name="promap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1349">promap :: Profunctor p => (a -> b, c -> d, p b c) -> p a d</a></code></h4>
+<h4 name="promap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1418">promap :: Profunctor p => (a -> b, c -> d, p b c) -> p a d</a></code></h4>
 
 Function wrapper for [`fantasy-land/promap`][].
 
@@ -560,7 +608,7 @@ built-in types: Function.
 11
 ```
 
-<h4 name="ap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1364">ap :: Apply f => (f (a -> b), f a) -> f b</a></code></h4>
+<h4 name="ap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1433">ap :: Apply f => (f (a -> b), f a) -> f b</a></code></h4>
 
 Function wrapper for [`fantasy-land/ap`][].
 
@@ -584,7 +632,7 @@ Identity(8)
 Cons(4, Cons(10, Cons(256, Cons(10000, Nil))))
 ```
 
-<h4 name="lift2"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1391">lift2 :: Apply f => (a -> b -> c, f a, f b) -> f c</a></code></h4>
+<h4 name="lift2"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1460">lift2 :: Apply f => (a -> b -> c, f a, f b) -> f c</a></code></h4>
 
 Lifts `a -> b -> c` to `Apply f => f a -> f b -> f c` and returns the
 result of applying this to the given arguments.
@@ -601,7 +649,7 @@ See also [`lift3`](#lift3).
 Identity(1000)
 ```
 
-<h4 name="lift3"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1411">lift3 :: Apply f => (a -> b -> c -> d, f a, f b, f c) -> f d</a></code></h4>
+<h4 name="lift3"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1480">lift3 :: Apply f => (a -> b -> c -> d, f a, f b, f c) -> f d</a></code></h4>
 
 Lifts `a -> b -> c -> d` to `Apply f => f a -> f b -> f c -> f d` and
 returns the result of applying this to the given arguments.
@@ -618,7 +666,7 @@ See also [`lift2`](#lift2).
 Identity('<baz>')
 ```
 
-<h4 name="apFirst"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1431">apFirst :: Apply f => (f a, f b) -> f a</a></code></h4>
+<h4 name="apFirst"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1500">apFirst :: Apply f => (f a, f b) -> f a</a></code></h4>
 
 Combines two effectful actions, keeping only the result of the first.
 Equivalent to Haskell's `(<*)` function.
@@ -635,7 +683,7 @@ See also [`apSecond`](#apSecond).
 Identity(1)
 ```
 
-<h4 name="apSecond"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1451">apSecond :: Apply f => (f a, f b) -> f b</a></code></h4>
+<h4 name="apSecond"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1520">apSecond :: Apply f => (f a, f b) -> f b</a></code></h4>
 
 Combines two effectful actions, keeping only the result of the second.
 Equivalent to Haskell's `(*>)` function.
@@ -652,7 +700,7 @@ See also [`apFirst`](#apFirst).
 Identity(2)
 ```
 
-<h4 name="of"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1471">of :: Applicative f => (TypeRep f, a) -> f a</a></code></h4>
+<h4 name="of"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1540">of :: Applicative f => (TypeRep f, a) -> f a</a></code></h4>
 
 Function wrapper for [`fantasy-land/of`][].
 
@@ -670,7 +718,7 @@ built-in types: Array and Function.
 Cons(42, Nil)
 ```
 
-<h4 name="chain"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1492">chain :: Chain m => (a -> m b, m a) -> m b</a></code></h4>
+<h4 name="chain"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1561">chain :: Chain m => (a -> m b, m a) -> m b</a></code></h4>
 
 Function wrapper for [`fantasy-land/chain`][].
 
@@ -688,7 +736,7 @@ Cons(1, Cons(3, Nil))
 'Hask'
 ```
 
-<h4 name="join"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1513">join :: Chain m => m (m a) -> m a</a></code></h4>
+<h4 name="join"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1582">join :: Chain m => m (m a) -> m a</a></code></h4>
 
 Removes one level of nesting from a nested monadic structure.
 
@@ -705,7 +753,7 @@ This function is derived from [`chain`](#chain).
 Identity(1)
 ```
 
-<h4 name="chainRec"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1533">chainRec :: ChainRec m => (TypeRep m, (a -> c, b -> c, a) -> m c, a) -> m b</a></code></h4>
+<h4 name="chainRec"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1602">chainRec :: ChainRec m => (TypeRep m, (a -> c, b -> c, a) -> m c, a) -> m b</a></code></h4>
 
 Function wrapper for [`fantasy-land/chainRec`][].
 
@@ -722,7 +770,7 @@ built-in types: Array.
 ['oo!', 'oo?', 'on!', 'on?', 'no!', 'no?', 'nn!', 'nn?']
 ```
 
-<h4 name="filter"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1553">filter :: (Applicative f, Foldable f, Monoid (f a)) => (a -> Boolean, f a) -> f a</a></code></h4>
+<h4 name="filter"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1622">filter :: (Applicative f, Foldable f, Monoid (f a)) => (a -> Boolean, f a) -> f a</a></code></h4>
 
 Filters its second argument in accordance with the given predicate.
 
@@ -739,7 +787,7 @@ See also [`filterM`](#filterM).
 Cons(1, Cons(3, Nil))
 ```
 
-<h4 name="filterM"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1576">filterM :: (Alternative m, Monad m) => (a -> Boolean, m a) -> m a</a></code></h4>
+<h4 name="filterM"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1645">filterM :: (Alternative m, Monad m) => (a -> Boolean, m a) -> m a</a></code></h4>
 
 Filters its second argument in accordance with the given predicate.
 
@@ -765,7 +813,7 @@ Nothing
 Just(1)
 ```
 
-<h4 name="alt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1607">alt :: Alt f => (f a, f a) -> f a</a></code></h4>
+<h4 name="alt"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1676">alt :: Alt f => (f a, f a) -> f a</a></code></h4>
 
 Function wrapper for [`fantasy-land/alt`][].
 
@@ -786,7 +834,7 @@ Just(1)
 Just(2)
 ```
 
-<h4 name="zero"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1631">zero :: Plus f => TypeRep f -> f a</a></code></h4>
+<h4 name="zero"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1700">zero :: Plus f => TypeRep f -> f a</a></code></h4>
 
 Function wrapper for [`fantasy-land/zero`][].
 
@@ -804,7 +852,7 @@ built-in types: Array and Object.
 Nothing
 ```
 
-<h4 name="reduce"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1652">reduce :: Foldable f => ((b, a) -> b, b, f a) -> b</a></code></h4>
+<h4 name="reduce"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1721">reduce :: Foldable f => ((b, a) -> b, b, f a) -> b</a></code></h4>
 
 Function wrapper for [`fantasy-land/reduce`][].
 
@@ -819,7 +867,7 @@ built-in types: Array and Object.
 'foobarbaz'
 ```
 
-<h4 name="traverse"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1670">traverse :: (Applicative f, Traversable t) => (TypeRep f, a -> f b, t a) -> f (t b)</a></code></h4>
+<h4 name="traverse"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1739">traverse :: (Applicative f, Traversable t) => (TypeRep f, a -> f b, t a) -> f (t b)</a></code></h4>
 
 Function wrapper for [`fantasy-land/traverse`][].
 
@@ -836,7 +884,7 @@ See also [`sequence`](#sequence).
 Identity([2, 3, 4])
 ```
 
-<h4 name="sequence"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1690">sequence :: (Applicative f, Traversable t) => (TypeRep f, t (f a)) -> f (t a)</a></code></h4>
+<h4 name="sequence"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1759">sequence :: (Applicative f, Traversable t) => (TypeRep f, t (f a)) -> f (t a)</a></code></h4>
 
 Inverts the given `t (f a)` to produce an `f (t a)`.
 
@@ -850,7 +898,7 @@ This function is derived from [`traverse`](#traverse).
 Identity([1, 2, 3])
 ```
 
-<h4 name="extend"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1707">extend :: Extend w => (w a -> b, w a) -> w b</a></code></h4>
+<h4 name="extend"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1776">extend :: Extend w => (w a -> b, w a) -> w b</a></code></h4>
 
 Function wrapper for [`fantasy-land/extend`][].
 
@@ -862,7 +910,7 @@ built-in types: Array.
 [4]
 ```
 
-<h4 name="extract"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1722">extract :: Comonad w => w a -> a</a></code></h4>
+<h4 name="extract"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1791">extract :: Comonad w => w a -> a</a></code></h4>
 
 Function wrapper for [`fantasy-land/extract`][].
 
@@ -871,7 +919,7 @@ Function wrapper for [`fantasy-land/extract`][].
 42
 ```
 
-<h4 name="contramap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.1.0/index.js#L1734">contramap :: Contravariant f => (b -> a, f a) -> f b</a></code></h4>
+<h4 name="contramap"><code><a href="https://github.com/sanctuary-js/sanctuary-type-classes/blob/v5.2.0/index.js#L1803">contramap :: Contravariant f => (b -> a, f a) -> f b</a></code></h4>
 
 Function wrapper for [`fantasy-land/contramap`][].
 
@@ -888,6 +936,7 @@ built-in types: Function.
 [Applicative]:              https://github.com/fantasyland/fantasy-land#applicative
 [Apply]:                    https://github.com/fantasyland/fantasy-land#apply
 [Bifunctor]:                https://github.com/fantasyland/fantasy-land#bifunctor
+[Category]:                 https://github.com/fantasyland/fantasy-land#category
 [Chain]:                    https://github.com/fantasyland/fantasy-land#chain
 [ChainRec]:                 https://github.com/fantasyland/fantasy-land#chainrec
 [Comonad]:                  https://github.com/fantasyland/fantasy-land#comonad
@@ -902,6 +951,7 @@ built-in types: Function.
 [Plus]:                     https://github.com/fantasyland/fantasy-land#plus
 [Profunctor]:               https://github.com/fantasyland/fantasy-land#profunctor
 [Semigroup]:                https://github.com/fantasyland/fantasy-land#semigroup
+[Semigroupoid]:             https://github.com/fantasyland/fantasy-land#semigroupoid
 [Setoid]:                   https://github.com/fantasyland/fantasy-land#setoid
 [Traversable]:              https://github.com/fantasyland/fantasy-land#traversable
 [`fantasy-land/alt`]:       https://github.com/fantasyland/fantasy-land#alt-method
@@ -909,12 +959,14 @@ built-in types: Function.
 [`fantasy-land/bimap`]:     https://github.com/fantasyland/fantasy-land#bimap-method
 [`fantasy-land/chain`]:     https://github.com/fantasyland/fantasy-land#chain-method
 [`fantasy-land/chainRec`]:  https://github.com/fantasyland/fantasy-land#chainrec-method
+[`fantasy-land/compose`]:   https://github.com/fantasyland/fantasy-land#compose-method
 [`fantasy-land/concat`]:    https://github.com/fantasyland/fantasy-land#concat-method
 [`fantasy-land/contramap`]: https://github.com/fantasyland/fantasy-land#contramap-method
 [`fantasy-land/empty`]:     https://github.com/fantasyland/fantasy-land#empty-method
 [`fantasy-land/equals`]:    https://github.com/fantasyland/fantasy-land#equals-method
 [`fantasy-land/extend`]:    https://github.com/fantasyland/fantasy-land#extend-method
 [`fantasy-land/extract`]:   https://github.com/fantasyland/fantasy-land#extract-method
+[`fantasy-land/id`]:        https://github.com/fantasyland/fantasy-land#id-method
 [`fantasy-land/lte`]:       https://github.com/fantasyland/fantasy-land#lte-method
 [`fantasy-land/map`]:       https://github.com/fantasyland/fantasy-land#map-method
 [`fantasy-land/of`]:        https://github.com/fantasyland/fantasy-land#of-method
diff --git a/package.json b/package.json
index d60ca9b..4cf1b4d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sanctuary-type-classes",
-  "version": "5.1.0",
+  "version": "5.2.0",
   "description": "Standard library for Fantasy Land",
   "license": "MIT",
   "repository": {