  This paper gives an accessible (but still technical) self-contained proof to
the fact that the intersection probabilities for planar Brownian motion are
given in terms of the intersection exponents, up to a bounded multiplicative
error, and some closely related results. While most of the results are already
known, the proofs are somewhat new, and the paper can serve as a source for the
estimates used in our paper on the analyticity of the Brownian intersection
exponents (math.PR/0005295).
