eqv returns false.equal returns true. i learn new things so eqv? and equal? is not the same thing.But i cannot thing anything about that I read the link.. <div class="gmail_quote">On Sun, Mar 1, 2009 at 9:18 PM, Jens Axel Soegaard <<a href="mailto:jensaxel@soegaard.net">jensaxel@soegaard.net</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">emre berat nebiog(lu skrev:<div><div class="Wj3C7c"> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Sorry for this newbie question.But i wonder so much about eqv? and equal?.In the some discussin that passes on ffreenode #scheme.I see some sentence which is "eqv? is faster than equal? in comparison.So i thought eqv? and equal? returns boolean thing #t or #f right ? So why? In that point,i have three question about that. what is the thing that makes eqv? faster than equal?. which one is more powerful on programming ? What is the reason that equal? still be used ? If eqv? is faster than equal?. </blockquote> </div></div> Read: <a href="http://www.schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%_sec_6.1" target="_blank">http://www.schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%_sec_6.1</a> Try to predict the result of: (eqv? (list 1 2) (list 1 2)) and (equal? (list 1 2) (list 1 2)) What happens and why? -- Jens Axel Søgaard </blockquote></div>