  Interference comes from coherent mixing. It can be suppressed by
entanglement, and the latter can be erased so as to revive interference. If the
entanglement is a mimal-term one (with minimal-term mixing), as is the case in
most thought and real experiments reported, there appears the possibility of
counter erasure and counter interference. This peculiar phenomenon of
minimal-term mixing and minimal-term entanglement is investigated in detail. In
particular, all two-term mixings of an (arbitrary) given minimal-term mixed
state are explicitly exhibited. And so are their possible laboratory
realizations in terms of distant ensemble decomposition.
