We present a boolean constraint logic language clp(B/FD) built upon a language over finite domains clp(FD) which uses a local propagation constraint solver. It is based on a single primitive constraint which allows the boolean solver to be encoded at a low-level. The boolean solver obtained in this way is both very simple and very efficient: on average it is eight times faster than the CHIP propagationbased boolean solver, i.e. nearly an order of magnitude faster, and infinitely better than the CHIP boolean unification solver. It also performs on average several times faster than special-purpose stand-alone boolean solvers.