<p>Hi guys, I am a freshman student in Kenya. After I stumbled on MIT's ocw website, I got interested in Scheme and after a few while on this LtU site, I felt like starting with DrScheme is the best way since its tailoured to the biginners. I am very new in Programming and we just don't have great teachers who have command of the subject here in Kenya.
<br>Well after installing and running DrScheme, I encountered a problem which I will be very greatful to anyone of you who can help.<br>I difined this procedure: (define (area-of-disk r)<br>(* 3.14 (* r r)))<br>which worked when I ran it like this (area-of-disk 5)
<p>then I defined this: (define (area-of-ring outer inner)<br>(- (area-of-disk outer)<br>(area-of-disk inner)))<br>However upon running this procedure I got this message; area-of-disk: name is not defined, not an argument, and not a primitive name.
<br>and this on the tracing window: No tracing results are available, yet. (Make sure that your language supports tracing and that tracing is enabled.)<br>Can anyone help?</p></div><br clear="all"><br>-- <br>Live, Learn, Love!