Decision tree complexity and Betti numbers

We show that any algebraic computation tree or any fixed-degree algebraic tree for solving the membership question of a compact set S ~ R“ must have height greater than Cl(log(@i(S))) – cn for each i, where pi(S) is the i-th Betti number. This generalizes a well-known result by Ben-Or [Be83] who proved this lower bound for the case i = O, and a recent result by Bjorner and Lovtisz [BL92] who proved this lower bound for all i for linear decision trees.