On the Nonexistence of Minimal Strong Partial Clones

Let k be a k-element set. We show that the lattice of all strong partial clones on k has no minimal elements. Moreover, we show that if C is a strong partial clone, then the family of all partial subclones of C is of continuum cardinality. We also show that in almost all cases, every strong partial clone contains a family of continuum cardinality of strong partial subclones.