In this paper we present
some new properties of the metric dimension defined by Bouligand in 1928
and prove the following new projection theorem: Let dimb(𝒜−𝒜) denote
the Bouligand dimension of the set 𝒜−𝒜 of differences between elements
of 𝒜. Given any compact set 𝒜⊆RN such that dimb(𝒜−𝒜) < m, then
almost every orthogonal projection P of 𝒜 of rank m is injective on 𝒜
and P|𝒜 has Lipschitz continuous inverse except for a logarithmic correction
term.