On 24 Mrz., 23:47, Virgil <vir...@ligriv.com> wrote: > In article > <ffdaee63-1e7b-4430-afb8-62c4bfe0a...@v20g2000yqj.googlegroups.com>, > > > > > > WM <mueck...@rz.fh-augsburg.de> wrote: > > On 24 Mrz., 02:30, Virgil <vir...@ligriv.com> wrote: > > > > Given: that deleting anyone set from a union of sets does not decrease > > > the union the set of remaining sets, > > > > THEN: Decreasing that union will require, if possible at all, deleting > > > more than one member set, but deleting more than one member set still > > > may not alsays decrease the union. > > > > Example: 100 different subsets each of 99 elements out of their union of > > > 100 elements. Then the union of the set of any two or more of them > > > equals the union of the set of all 100 of them. > > > Enumerate the sets. Then there will be a first set that, when > > subtracted from the union, will change the union of the remaining > > sets. > > In every ennumeration it will be the 99th set, but in different > ennumerations it will be usually a different one of the original set.
My proof concerns the natural enumeration of FISONs. And there it holds.