Noise margins in high speed digital systems continue to erode. Full differe
ntial signal routing provides a mechanism for deferring these effects, This
paper proposes a three stage routing process for solving the adjacent plac
ement routing problem of differential signal pairs, and proves that it is o
ptimal. The process views differential pairs as logical nets; routes the lo
gical nets; then bifurcates the result to achieve a physical realization. F
inite stale machine theory provides the critical theoretical underpinning a
nd formal proof of correctness necessary for linear time bifurcation. Regul
ar expressions map the theoretical solution to an appropriate implementatio
n strategy that employs feature vectors for net recognition.