diff --git a/README.md b/README.md
index eb03325..82d634c 100644
--- a/README.md
+++ b/README.md
@@ -196,6 +196,58 @@ fn not_example() -> Result<(), Error<u8>> {
 }
 ```
 
+### 4: `If` Rule Composer
+
+`If` Rule Composer is a rule that applies a specific rule only when a certain condition is met.
+
+```rust
+type Target = Refined<If<GreaterEqualRuleI8<10>, EvenRuleI8>>;
+
+fn if_example() -> Result<(), Error<i8>> {
+    let target = Target::new(8)?;
+    assert_eq!(target.into_value(), 8);
+
+    let target = Target::new(9)?;
+    assert_eq!(target.into_value(), 9);
+
+    let target = Target::new(10)?;
+    assert_eq!(target.into_value(), 10);
+
+    let target = Target::new(11);
+    assert!(target.is_err());
+
+    Ok(())
+}
+```
+
+### 5: `IfElse` Rule Composer
+
+`IfElse` Rule Composer is a rule that applies a specific rule when a certain condition is met and another rule when it is not met.
+
+```rust
+type Target = Refined<IfElse<GreaterEqualRuleI8<10>, EvenRuleI8, OddRuleI8>>;
+
+fn if_else_example() -> Result<(), Error<i8>> {
+    let target = Target::new(8);
+    assert!(target.is_err());
+
+    let target = Target::new(9)?;
+    assert_eq!(target.into_value(), 9);
+
+    let target = Target::new(10)?;
+    assert_eq!(target.into_value(), 10);
+
+    let target = Target::new(11);
+    assert!(target.is_err());
+
+    Ok(())
+}
+```
+
+### 6: Other Rule Composer
+
+`Equiv`, `Nand`, `Nor` and `Xor` are also available.
+
 # Number
 
 ## `MinMax`
diff --git a/tests/read_me.rs b/tests/read_me.rs
index cd7093c..e7de9f8 100644
--- a/tests/read_me.rs
+++ b/tests/read_me.rs
@@ -2,12 +2,13 @@ use serde::{Deserialize, Serialize};
 use serde_json::json;
 
 use refined_type::result::Error;
-use refined_type::rule::composer::Not;
+use refined_type::rule::composer::{If, IfElse, Not};
 use refined_type::rule::{
-    EqualU8, ExistsVec, ForAllVec, GreaterEqualU8, GreaterU8, HeadVec, IndexRuleVec, IndexVec,
-    InitVec, LastVec, LengthDefinition, LengthEqual, LengthEqualRule, LengthGreater, LengthLess,
-    LengthMinMax, LessEqualU8, LessU8, MinMaxU8, NonEmptyString, NonEmptyStringRule, NonEmptyVec,
-    NonEmptyVecDeque, RangeU8, Reverse, Rule, SkipFirst, SkipVec, TailVec,
+    EqualU8, EvenRuleI8, ExistsVec, ForAllVec, GreaterEqualRuleI8, GreaterEqualU8, GreaterU8,
+    HeadVec, IndexRuleVec, IndexVec, InitVec, LastVec, LengthDefinition, LengthEqual,
+    LengthEqualRule, LengthGreater, LengthLess, LengthMinMax, LessEqualU8, LessU8, MinMaxU8,
+    NonEmptyString, NonEmptyStringRule, NonEmptyVec, NonEmptyVecDeque, OddRuleI8, RangeU8, Reverse,
+    Rule, SkipFirst, SkipVec, TailVec,
 };
 use refined_type::{And, Or, Refined};
 
@@ -660,3 +661,41 @@ fn custom_length_example() -> Result<(), Error<Hello>> {
     assert_eq!(hello.into_value(), Hello);
     Ok(())
 }
+
+#[test]
+fn if_example() -> Result<(), Error<i8>> {
+    type Target = Refined<If<GreaterEqualRuleI8<10>, EvenRuleI8>>;
+
+    let target = Target::new(8)?;
+    assert_eq!(target.into_value(), 8);
+
+    let target = Target::new(9)?;
+    assert_eq!(target.into_value(), 9);
+
+    let target = Target::new(10)?;
+    assert_eq!(target.into_value(), 10);
+
+    let target = Target::new(11);
+    assert!(target.is_err());
+
+    Ok(())
+}
+
+#[test]
+fn if_else_example() -> Result<(), Error<i8>> {
+    type Target = Refined<IfElse<GreaterEqualRuleI8<10>, EvenRuleI8, OddRuleI8>>;
+
+    let target = Target::new(8);
+    assert!(target.is_err());
+
+    let target = Target::new(9)?;
+    assert_eq!(target.into_value(), 9);
+
+    let target = Target::new(10)?;
+    assert_eq!(target.into_value(), 10);
+
+    let target = Target::new(11);
+    assert!(target.is_err());
+
+    Ok(())
+}