Dear All,

I want to do two mathematical operations, say

`a / b`

and

`c / d`

then test whether they are equal. I'm really very bad at computer errors, I think I need to read more about it (any reference is welcome). So, my question is: What is a suitable EPSILON to tolerate some computational errors in general? I know this depends on the complexity of the operation itself (because of propagating the errors at different steps of computation)... but what is a suitable start?

```
bool equals(double n1, double n2)
{
return ((n1 - n2 <= EPSILON) || (n2 - n1 <= EPSILON));
}
```