0ohm resistor, why?

[John_Rae]

and the only situation where, if both resistors are 0R0, two resistors in series is the same as two resistors in parallel ie R1 + R2 = R1 x R2 / (R1 + R2) which equates to R1² + (2 x R1 x R2) + R2² = R1 + R2

Wot a load of rot