  We present a novel way to encode compositional information in
high-dimensional (HD) vectors. Inspired by chromosomal crossover, random HD
vectors are recursively interwoven, with a fraction of one vector's components
masked out and replaced by those from another using a context-dependent mask.
Unlike many HD computing schemes, "crossover" codes highly overlap with their
base elements' and sub-structures' codes without sacrificing relational
information, allowing fast element readout and decoding by greedy
reconstruction. Crossover is mathematically tractable and has several
properties desirable for robust, flexible representation.
