NMSU • BLAST-2009
Something Old, Something New, Something Borrowed, ...
Next F.E.J. Linton • Wesleyan Univ. Math/CS Emeritus

V nbds meet   Distinct reals x, y in Xελ must lie at least 2ε apart: |x - y| > 2ε. For if instead 0 < |x – y| < 2ε , then
Vε(x) ∩ Vε(y) = {(½(x+y), ½|x-y|)} ≠ ∅, 
while ...