I want to do two things in R and have searched the mail archive and packages to see if they have been done before. I could not see anything. If anyone has tackled these problem domains before I would be grateful for help. 1. Has anyone implemented interval arithmetic (see generally http://www.cs.utep.edu/interval-comp/ ) either directly in R code or by linking in an external C++/Fortran library? 2. Has anyone implemented queueing modelling ( see e.g the software at http://www.perfdynamics.com/ ). I would be grateful for pointers. Please include me as an addressee on any response as I am not on this mailing list. regards Dominic