<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=us-ascii" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 11.00.9600.16476"></HEAD> <BODY> <DIV><FONT size=2 face="Courier New"><SPAN class=765280022-27012014>Hi to all,</SPAN></FONT></DIV> <DIV><FONT size=2 face="Courier New"><SPAN class=765280022-27012014>Section "3.6 symbols" of the Racket reference manual states:</SPAN></FONT></DIV> <DIV><FONT size=2 face="Courier New"><SPAN class=765280022-27012014></SPAN></FONT> </DIV> <DIV><FONT size=2 face="Courier New"><SPAN class=765280022-27012014>Interned and unreadable symbols are only weakly held ... but a symbol maay disappear when ... used as the key in a weak hash table ..."</SPAN></FONT></DIV> <DIV><FONT size=2 face="Courier New"><SPAN class=765280022-27012014></SPAN></FONT> </DIV></BODY></HTML>