Clonal Ding–Oporowski–Oxley–Vertigan-type minor conjecture

Let $m$ be a positive integer, and let $M$ be a $3$-connected clonal matroid. The matroids $U_{2,2m}$ and $U_{2m-2,2m}$ are uniform matroids, while $\Lambda_m$ and $\Delta_m$ denote the named matroids used in the source. Clonal minor conjecture. There is a function $f(m)$ such that, if $M$ has at least $f(m)$ elements, then $M$ has one of the following as a clonal minor: $U_{2,2m}$, $U_{2m-2,2m}$, $\Lambda_m$, or $\Delta_m$.

The conjecture is presented as a possible strengthening of the theorem proved in the chapter: the desired conclusion is that one of these structured minors can be found while retaining clonal structure. No resolution is given in the supplied text.