Interpolation in ortholattices
arXiv:math/0002237
Abstract
If L is a complete ortholattice, f any partial function from L^n to L, then there is a complete ortholattice L* containing L as a subortholattice, and an ortholattice polynomial with coefficients in L* which represents f on L^n. Iterating this construction long enough yields a complete ortholattice in which every function can be interpolated by a polynomial on any set of small enough cardinality.
6 pages. See also http://info.tuwien.ac.at/goldstern/papers/index.html#ortho