I hate that mantra, as it produced more bugs and inaccuracies in the code I have to work with than necessary. Actually you should be able to rely on the equality of a value with its copy no matter what. We are past the FPU days, so I think we can let go of these mindless epsilons sprinkled over the code.

(Even during the FPU days, every ; should have rounded each value to the size of the variables, unless you use a special compiler switch to make FP math faster)

Absolutely, and the fix involved adding a tolerance check. Not my code, I was the new guy at the time, and my job was trying to fix the bugs nobody else wanted to deal with...