 The  <a href = "http://www.cs.cornell.edu/Info/People/jackson/papers/ab-alg-abstract.html"> abstract </a> is available, as is the full text in  <a href="http://www.cs.cornell.edu/Info/People/jackson/papers/abalg.dvi.gz">dvi</a>(25K) and  <a href="http://www.cs.cornell.edu/Info/People/jackson/papers/abalg.ps.gz">postscript</a>(59K) formats. <p>
