[r-t] Asymmetric Plain Minor Methods

[Robin Woolley]

Hi All.

It is said that extents of the above class of methods, Asymmetric Plain 
Minor Methods, cannot generally be found.
However, it seems possible to find extents of some of them. The latest one 
which has come to my notice is this one: x4.2.3.2.5x3x4x, 2nds.

What is the general situation regarding such methods? The above is just a 
front-work variation of Double Oxford.

Best wishes
Robin