R-beta: NaN & Inf

Can someone explain what this words (NaN and Inf) mean ? I get then as a 
result of some matrix operations, in the end I have a matrix without any 
figures just this words.

NaN=Not a Number (e.g. 0/0=NaN)
  Inf=Machine Infinity (e.g. 1/0=NaN)
  
  In addition, x*NaN = NaN x*Inf=[+/-]Inf NaN*Inf=NaN and so on.
  
  guido masarotto
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._