diff --git a/Behavioral/Specification/AbstractSpecification.php b/Behavioral/Specification/AbstractSpecification.php
deleted file mode 100644
index 66d61b8..0000000
--- a/Behavioral/Specification/AbstractSpecification.php
+++ /dev/null
@@ -1,52 +0,0 @@
-<?php
-
-namespace DesignPatterns\Behavioral\Specification;
-
-/**
- * An abstract specification allows the creation of wrapped specifications.
- */
-abstract class AbstractSpecification implements SpecificationInterface
-{
-    /**
-     * Checks if given item meets all criteria.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    abstract public function isSatisfiedBy(Item $item);
-
-    /**
-     * Creates a new logical AND specification.
-     *
-     * @param SpecificationInterface $spec
-     *
-     * @return SpecificationInterface
-     */
-    public function plus(SpecificationInterface $spec)
-    {
-        return new Plus($this, $spec);
-    }
-
-    /**
-     * Creates a new logical OR composite specification.
-     *
-     * @param SpecificationInterface $spec
-     *
-     * @return SpecificationInterface
-     */
-    public function either(SpecificationInterface $spec)
-    {
-        return new Either($this, $spec);
-    }
-
-    /**
-     * Creates a new logical NOT specification.
-     *
-     * @return SpecificationInterface
-     */
-    public function not()
-    {
-        return new Not($this);
-    }
-}
diff --git a/Behavioral/Specification/AndSpecification.php b/Behavioral/Specification/AndSpecification.php
new file mode 100644
index 0000000..c6a88ea
--- /dev/null
+++ b/Behavioral/Specification/AndSpecification.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace DesignPatterns\Behavioral\Specification;
+
+class AndSpecification implements SpecificationInterface
+{
+    /**
+     * @var SpecificationInterface[]
+     */
+    private $specifications;
+
+    /**
+     * @param SpecificationInterface[] ...$specifications
+     */
+    public function __construct(SpecificationInterface ...$specifications)
+    {
+        $this->specifications = $specifications;
+    }
+
+    public function isSatisfiedBy(Item $item): bool
+    {
+        $satisfied = [];
+
+        foreach ($this->specifications as $specification) {
+            $satisfied[] = $specification->isSatisfiedBy($item);
+        }
+
+        return !in_array(false, $satisfied);
+    }
+}
diff --git a/Behavioral/Specification/Either.php b/Behavioral/Specification/Either.php
deleted file mode 100644
index a30372a..0000000
--- a/Behavioral/Specification/Either.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-
-namespace DesignPatterns\Behavioral\Specification;
-
-/**
- * A logical OR specification.
- */
-class Either extends AbstractSpecification
-{
-    protected $left;
-    protected $right;
-
-    /**
-     * A composite wrapper of two specifications.
-     *
-     * @param SpecificationInterface $left
-     * @param SpecificationInterface $right
-     */
-    public function __construct(SpecificationInterface $left, SpecificationInterface $right)
-    {
-        $this->left = $left;
-        $this->right = $right;
-    }
-
-    /**
-     * Returns the evaluation of both wrapped specifications as a logical OR.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    public function isSatisfiedBy(Item $item)
-    {
-        return $this->left->isSatisfiedBy($item) || $this->right->isSatisfiedBy($item);
-    }
-}
diff --git a/Behavioral/Specification/Item.php b/Behavioral/Specification/Item.php
index 8d639e0..a167f0a 100644
--- a/Behavioral/Specification/Item.php
+++ b/Behavioral/Specification/Item.php
@@ -2,29 +2,19 @@
 
 namespace DesignPatterns\Behavioral\Specification;
 
-/**
- * An trivial item.
- */
 class Item
 {
-    protected $price;
-
     /**
-     * An item must have a price.
-     *
-     * @param int $price
+     * @var float
      */
-    public function __construct($price)
+    private $price;
+
+    public function __construct(float $price)
     {
         $this->price = $price;
     }
 
-    /**
-     * Get the items price.
-     *
-     * @return int
-     */
-    public function getPrice()
+    public function getPrice(): float
     {
         return $this->price;
     }
diff --git a/Behavioral/Specification/Not.php b/Behavioral/Specification/Not.php
deleted file mode 100644
index e99a6cc..0000000
--- a/Behavioral/Specification/Not.php
+++ /dev/null
@@ -1,33 +0,0 @@
-<?php
-
-namespace DesignPatterns\Behavioral\Specification;
-
-/**
- * A logical Not specification.
- */
-class Not extends AbstractSpecification
-{
-    protected $spec;
-
-    /**
-     * Creates a new specification wrapping another.
-     *
-     * @param SpecificationInterface $spec
-     */
-    public function __construct(SpecificationInterface $spec)
-    {
-        $this->spec = $spec;
-    }
-
-    /**
-     * Returns the negated result of the wrapped specification.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    public function isSatisfiedBy(Item $item)
-    {
-        return !$this->spec->isSatisfiedBy($item);
-    }
-}
diff --git a/Behavioral/Specification/NotSpecification.php b/Behavioral/Specification/NotSpecification.php
new file mode 100644
index 0000000..db47b51
--- /dev/null
+++ b/Behavioral/Specification/NotSpecification.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace DesignPatterns\Behavioral\Specification;
+
+class NotSpecification implements SpecificationInterface
+{
+    /**
+     * @var SpecificationInterface
+     */
+    private $specification;
+
+    public function __construct(SpecificationInterface $specification)
+    {
+        $this->specification = $specification;
+    }
+
+    public function isSatisfiedBy(Item $item): bool
+    {
+        return !$this->specification->isSatisfiedBy($item);
+    }
+}
diff --git a/Behavioral/Specification/OrSpecification.php b/Behavioral/Specification/OrSpecification.php
new file mode 100644
index 0000000..62a4e08
--- /dev/null
+++ b/Behavioral/Specification/OrSpecification.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace DesignPatterns\Behavioral\Specification;
+
+class OrSpecification implements SpecificationInterface
+{
+    /**
+     * @var SpecificationInterface[]
+     */
+    private $specifications;
+
+    /**
+     * @param SpecificationInterface[] ...$specifications
+     */
+    public function __construct(SpecificationInterface ...$specifications)
+    {
+        $this->specifications = $specifications;
+    }
+
+    public function isSatisfiedBy(Item $item): bool
+    {
+        $satisfied = [];
+
+        foreach ($this->specifications as $specification) {
+            $satisfied[] = $specification->isSatisfiedBy($item);
+        }
+
+        return in_array(true, $satisfied);
+    }
+}
diff --git a/Behavioral/Specification/Plus.php b/Behavioral/Specification/Plus.php
deleted file mode 100644
index 26bd585..0000000
--- a/Behavioral/Specification/Plus.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-
-namespace DesignPatterns\Behavioral\Specification;
-
-/**
- * A logical AND specification.
- */
-class Plus extends AbstractSpecification
-{
-    protected $left;
-    protected $right;
-
-    /**
-     * Creation of a logical AND of two specifications.
-     *
-     * @param SpecificationInterface $left
-     * @param SpecificationInterface $right
-     */
-    public function __construct(SpecificationInterface $left, SpecificationInterface $right)
-    {
-        $this->left = $left;
-        $this->right = $right;
-    }
-
-    /**
-     * Checks if the composite AND of specifications passes.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    public function isSatisfiedBy(Item $item)
-    {
-        return $this->left->isSatisfiedBy($item) && $this->right->isSatisfiedBy($item);
-    }
-}
diff --git a/Behavioral/Specification/PriceSpecification.php b/Behavioral/Specification/PriceSpecification.php
index 2019ad2..3b54586 100644
--- a/Behavioral/Specification/PriceSpecification.php
+++ b/Behavioral/Specification/PriceSpecification.php
@@ -2,47 +2,35 @@
 
 namespace DesignPatterns\Behavioral\Specification;
 
-/**
- * A specification to check an Item is priced between min and max.
- */
-class PriceSpecification extends AbstractSpecification
+class PriceSpecification implements SpecificationInterface
 {
-    protected $maxPrice;
-    protected $minPrice;
+    /**
+     * @var float|null
+     */
+    private $maxPrice;
 
     /**
-     * Sets the optional maximum price.
-     *
-     * @param int $maxPrice
+     * @var float|null
      */
-    public function setMaxPrice($maxPrice)
+    private $minPrice;
+
+    /**
+     * @param float $minPrice
+     * @param float $maxPrice
+     */
+    public function __construct($minPrice, $maxPrice)
     {
+        $this->minPrice = $minPrice;
         $this->maxPrice = $maxPrice;
     }
 
-    /**
-     * Sets the optional minimum price.
-     *
-     * @param int $minPrice
-     */
-    public function setMinPrice($minPrice)
+    public function isSatisfiedBy(Item $item): bool
     {
-        $this->minPrice = $minPrice;
-    }
-
-    /**
-     * Checks if Item price falls between bounds.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    public function isSatisfiedBy(Item $item)
-    {
-        if (!empty($this->maxPrice) && $item->getPrice() > $this->maxPrice) {
+        if ($this->maxPrice !== null && $item->getPrice() > $this->maxPrice) {
             return false;
         }
-        if (!empty($this->minPrice) && $item->getPrice() < $this->minPrice) {
+
+        if ($this->minPrice !== null && $item->getPrice() < $this->minPrice) {
             return false;
         }
 
diff --git a/Behavioral/Specification/README.rst b/Behavioral/Specification/README.rst
index b6957e0..84d6913 100644
--- a/Behavioral/Specification/README.rst
+++ b/Behavioral/Specification/README.rst
@@ -38,15 +38,9 @@ SpecificationInterface.php
    :language: php
    :linenos:
 
-AbstractSpecification.php
+OrSpecification.php
 
-.. literalinclude:: AbstractSpecification.php
-   :language: php
-   :linenos:
-
-Either.php
-
-.. literalinclude:: Either.php
+.. literalinclude:: OrSpecification.php
    :language: php
    :linenos:
 
@@ -56,15 +50,15 @@ PriceSpecification.php
    :language: php
    :linenos:
 
-Plus.php
+AndSpecification.php
 
-.. literalinclude:: Plus.php
+.. literalinclude:: AndSpecification.php
    :language: php
    :linenos:
 
-Not.php
+NotSpecification.php
 
-.. literalinclude:: Not.php
+.. literalinclude:: NotSpecification.php
    :language: php
    :linenos:
 
diff --git a/Behavioral/Specification/SpecificationInterface.php b/Behavioral/Specification/SpecificationInterface.php
index 796af9f..7387700 100644
--- a/Behavioral/Specification/SpecificationInterface.php
+++ b/Behavioral/Specification/SpecificationInterface.php
@@ -2,36 +2,7 @@
 
 namespace DesignPatterns\Behavioral\Specification;
 
-/**
- * An interface for a specification.
- */
 interface SpecificationInterface
 {
-    /**
-     * A boolean evaluation indicating if the object meets the specification.
-     *
-     * @param Item $item
-     *
-     * @return bool
-     */
-    public function isSatisfiedBy(Item $item);
-
-    /**
-     * Creates a logical AND specification.
-     *
-     * @param SpecificationInterface $spec
-     */
-    public function plus(SpecificationInterface $spec);
-
-    /**
-     * Creates a logical OR specification.
-     *
-     * @param SpecificationInterface $spec
-     */
-    public function either(SpecificationInterface $spec);
-
-    /**
-     * Creates a logical not specification.
-     */
-    public function not();
+    public function isSatisfiedBy(Item $item): bool;
 }
diff --git a/Behavioral/Specification/Tests/SpecificationTest.php b/Behavioral/Specification/Tests/SpecificationTest.php
index 5abc82a..d7676a4 100644
--- a/Behavioral/Specification/Tests/SpecificationTest.php
+++ b/Behavioral/Specification/Tests/SpecificationTest.php
@@ -3,101 +3,44 @@
 namespace DesignPatterns\Behavioral\Specification\Tests;
 
 use DesignPatterns\Behavioral\Specification\Item;
+use DesignPatterns\Behavioral\Specification\NotSpecification;
+use DesignPatterns\Behavioral\Specification\OrSpecification;
+use DesignPatterns\Behavioral\Specification\AndSpecification;
 use DesignPatterns\Behavioral\Specification\PriceSpecification;
 
-/**
- * SpecificationTest tests the specification pattern.
- */
 class SpecificationTest extends \PHPUnit_Framework_TestCase
 {
-    public function testSimpleSpecification()
+    public function testCanOr()
     {
-        $item = new Item(100);
-        $spec = new PriceSpecification();
+        $spec1 = new PriceSpecification(50, 99);
+        $spec2 = new PriceSpecification(101, 200);
 
-        $this->assertTrue($spec->isSatisfiedBy($item));
+        $orSpec = new OrSpecification($spec1, $spec2);
 
-        $spec->setMaxPrice(50);
-        $this->assertFalse($spec->isSatisfiedBy($item));
-
-        $spec->setMaxPrice(150);
-        $this->assertTrue($spec->isSatisfiedBy($item));
-
-        $spec->setMinPrice(101);
-        $this->assertFalse($spec->isSatisfiedBy($item));
-
-        $spec->setMinPrice(100);
-        $this->assertTrue($spec->isSatisfiedBy($item));
+        $this->assertFalse($orSpec->isSatisfiedBy(new Item(100)));
+        $this->assertTrue($orSpec->isSatisfiedBy(new Item(51)));
+        $this->assertTrue($orSpec->isSatisfiedBy(new Item(150)));
     }
 
-    public function testNotSpecification()
+    public function testCanAnd()
     {
-        $item = new Item(100);
-        $spec = new PriceSpecification();
-        $not = $spec->not();
+        $spec1 = new PriceSpecification(50, 100);
+        $spec2 = new PriceSpecification(80, 200);
 
-        $this->assertFalse($not->isSatisfiedBy($item));
+        $orSpec = new AndSpecification($spec1, $spec2);
 
-        $spec->setMaxPrice(50);
-        $this->assertTrue($not->isSatisfiedBy($item));
-
-        $spec->setMaxPrice(150);
-        $this->assertFalse($not->isSatisfiedBy($item));
-
-        $spec->setMinPrice(101);
-        $this->assertTrue($not->isSatisfiedBy($item));
-
-        $spec->setMinPrice(100);
-        $this->assertFalse($not->isSatisfiedBy($item));
+        $this->assertFalse($orSpec->isSatisfiedBy(new Item(150)));
+        $this->assertFalse($orSpec->isSatisfiedBy(new Item(1)));
+        $this->assertFalse($orSpec->isSatisfiedBy(new Item(51)));
+        $this->assertTrue($orSpec->isSatisfiedBy(new Item(100)));
     }
 
-    public function testPlusSpecification()
+    public function testCanNot()
     {
-        $spec1 = new PriceSpecification();
-        $spec2 = new PriceSpecification();
-        $plus = $spec1->plus($spec2);
+        $spec1 = new PriceSpecification(50, 100);
+        $orSpec = new NotSpecification($spec1);
 
-        $item = new Item(100);
-
-        $this->assertTrue($plus->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(150);
-        $spec2->setMinPrice(50);
-        $this->assertTrue($plus->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(150);
-        $spec2->setMinPrice(101);
-        $this->assertFalse($plus->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(99);
-        $spec2->setMinPrice(50);
-        $this->assertFalse($plus->isSatisfiedBy($item));
-    }
-
-    public function testEitherSpecification()
-    {
-        $spec1 = new PriceSpecification();
-        $spec2 = new PriceSpecification();
-        $either = $spec1->either($spec2);
-
-        $item = new Item(100);
-
-        $this->assertTrue($either->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(150);
-        $spec2->setMaxPrice(150);
-        $this->assertTrue($either->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(150);
-        $spec2->setMaxPrice(0);
-        $this->assertTrue($either->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(0);
-        $spec2->setMaxPrice(150);
-        $this->assertTrue($either->isSatisfiedBy($item));
-
-        $spec1->setMaxPrice(99);
-        $spec2->setMaxPrice(99);
-        $this->assertFalse($either->isSatisfiedBy($item));
+        $this->assertTrue($orSpec->isSatisfiedBy(new Item(150)));
+        $this->assertFalse($orSpec->isSatisfiedBy(new Item(50)));
     }
 }