devdocs/elisp/evaluation-notation.html


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 <h4 class="subsection">Evaluation Notation</h4>    <p>A Lisp expression that you can evaluate is called a <em>form</em>. Evaluating a form always produces a result, which is a Lisp object. In the examples in this manual, this is indicated with ‘<samp>⇒</samp>’: </p> <div class="example"> <pre class="example">(car '(1 2))
     ⇒ 1
</pre>
</div> <p>You can read this as “<code>(car '(1 2))</code> evaluates to 1”. </p> <p>When a form is a macro call, it expands into a new form for Lisp to evaluate. We show the result of the expansion with ‘<samp>→</samp>’. We may or may not show the result of the evaluation of the expanded form. </p> <div class="example"> <pre class="example">(third '(a b c))
     → (car (cdr (cdr '(a b c))))
     ⇒ c
</pre>
</div> <p>To help describe one form, we sometimes show another form that produces identical results. The exact equivalence of two forms is indicated with ‘<samp>≡</samp>’. </p> <div class="example"> <pre class="example">(make-sparse-keymap) ≡ (list 'keymap)
</pre>
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