 'a' to 'c'. By default, for
        POSIX-Extended regular expressions, a character <span class="emphasis"><em>x</em></span> is
        within the range <span class="emphasis"><em>y</em></span> to <span class="emphasis"><em>z</em></span>, if it
        collates within that range; this results in locale specific behavior . This
        behavior can be turned off by unsetting the <code class="computeroutput"><span class="identifier">collate</span></code>
        <a class="link" href="../ref/syntax_option_typ