>> In real reality, 3.1 is based on 3.0, which is based on 2.1,
>> which is based on 2.0(x), which is based on 1.3(.x).

> 2.1 is based on 3.0 not the other way round.

Indeed, thanks for correction. In my defence, the whole 2.x series completely escaped me as I jumped directly from 1.3 (A500) to 3.0 (A4000) in 1994.