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    <p><img src="https://i.stack.imgur.com/Nmrml.jpg" alt="enter image description here"></p> <p>CLOS is an object system, where CLOS concepts itself are first-class objects. Classes themselves are instances - of a meta class. There is some circularity involved.</p> <p>There is an instance <code>standard-object</code>. It's an instance of <code>standard-class</code>. It is a class itself. All standard CLOS objects will have it as a superclass. There are other types of objects, for example structures. So <code>standard-object</code> is there as a superclass for all typical CLOS objects.</p> <p><code>standard-class</code> is in instance of itself. It is the class of all class objects. Since <code>standard-object</code> is also a class, the instance for the class <code>standard-object</code> is an instance of the class <code>standard-class</code>. Since all standard classes are also CLOS objects, <code>standard-class</code> inherits from <code>standard-object</code>.</p> <pre><code>CL-USER 22 &gt; (class-of (find-class 'standard-object)) #&lt;STANDARD-CLASS STANDARD-CLASS 40F016A063&gt; </code></pre> <p>The class of the <code>standard-object</code> class object is <code>standard-class</code>.</p> <pre><code>CL-USER 23 &gt; (class-of (find-class 'standard-class)) #&lt;STANDARD-CLASS STANDARD-CLASS 40F016A063&gt; </code></pre> <p>The class of the <code>standard-class</code> class object is <code>standard-class</code>.</p> <pre><code>CL-USER 24 &gt; (find-class 'standard-object) #&lt;STANDARD-CLASS STANDARD-OBJECT 40F017732B&gt; </code></pre> <p>The class <code>standard-object</code> is itself an object and a class. It is a superclass of all CLOS objects.</p> <pre><code>CL-USER 25 &gt; (find-class 'standard-class) #&lt;STANDARD-CLASS STANDARD-CLASS 40F016A063&gt; </code></pre> <p>The class <code>standard-class</code> is itself an object and a class. It is a superclass of all CLOS classes.</p>
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    1. POHierarchy of standard-object and standard-class in Common Lisp
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    1. USRainer Joswig
    1. USRainer Joswig
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    1. COThank you! With these examples it seems I understand now.
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    2. COstarting at p. 306 in Appendix D. of The Art of the Metaobject Protocol, shows code to bootstrap a CLOS-like language; includes how all of the circularity is detangled; I found it informative, although I can't yet say that I completely understand it.
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      1. USClayton Stanley
 

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