Yet another DIY RPN calculator

[ttw]

If you have access to a modern floating-point CPU, you may consider implementing interval arithmetic to handle errors. It's fairly hard in software though. It's also important to implement some things like the interval Newton method which can shrink intervals faster than one might think. (One calculates upper and lower bounds on the putative answer and then takes the intersection of this interval with the previous; because of the interval intersection part, one can get really nice contractions, still no better than quadratic.)

There are some other interval things but I haven't kept up.