Universal Distance Algebra
A linear projection plus symbolic quantization preserves pairwise euclidean distances by construction. Anything that produces an euclidean feature space — text embedding, audio frame, image patch, sensor frame, biosignal — passes through the same downstream pipeline.
Johnson–Lindenstrauss (1984) guarantees distance preservation under random linear projection; Achlioptas (2003) extends this to sparse projections with discrete entries; Charikar (2002) shows sign-based quantization yields ε-approximation of cosine distance.
