  We present new algorithms to compute fundamental properties of a Boolean
function given in truth-table form. Specifically, we give an O(N^2.322 log N)
algorithm for block sensitivity, an O(N^1.585 log N) algorithm for `tree
decomposition,' and an O(N) algorithm for `quasisymmetry.' These algorithms are
based on new insights into the structure of Boolean functions that may be of
independent interest. We also give a subexponential-time algorithm for the
space-bounded quantum query complexity of a Boolean function. To prove this
algorithm correct, we develop a theory of limited-precision representation of
unitary operators, building on work of Bernstein and Vazirani.
