<html><head><base href="x-msg://1534/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>How did you produce this error message? </div><div><br></div><div>When I run this program: </div><div><br></div><div><div> (require htdp/master)</div><div> (define (check-color x y z w) x)</div><div> (master check-color)</div></div><div><br></div><div>I get no error whatsoever. I also don't get an error when I run </div><div><br></div><div> > (master check-color)</div><div><br></div><div>in the interactions area: </div><div><br></div><div><div>Welcome to DrRacket, version 5.0.99.3--2010-11-29(f11e53c/g) [3m].</div><div>Language: Beginning Student.</div><div>> (master check-color)</div><div>true</div><div>></div><div><br></div><div>-- Matthias</div><div> </div></div><div><br></div><br><div><div>On Nov 28, 2010, at 6:58 AM, ΠΟΘͺ wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="margin-top: 10px; margin-right: 10px; margin-bottom: 10px; margin-left: 10px; font-family: verdana; font-size: 10pt; "><div><font size="2" face="Verdana"></font> </div><div><font size="2" face="Verdana">Hi:</font></div><div> </div><div>Help Me! Thanks! <div> </div><div>> (master check-color)</div><div>check-color: this is a procedure, so it must be applied to arguments (which requires using a parenthesis before the name)</div><div> </div><div> </div></div><div align="left"><font color="#c0c0c0" size="2" face="Verdana">2010-11-28</font></div><font size="2" face="Verdana"><hr align="left" size="2" style="width: 122px; height: 2px; "><div><font color="#c0c0c0" size="2" face="Verdana"><span>Q.Xing</span></font></div></font>_________________________________________________<br> For list-related administrative tasks:<br> <a href="http://lists.racket-lang.org/listinfo/users">http://lists.racket-lang.org/listinfo/users</a></div></blockquote></div><br></body></html>