Fast membership performance

      y←?200⍴1e9                 ⍝ The algorithm is branchless,
      x←?1e6⍴1e9                 ⍝ so the data doesn't matter
      ⊢t←1e6×1 0 0 5 cmpx 'x∊y'  ⍝ Time per element in ps
759.8876953
      t×3.483×1e¯3               ⍝ in cycles
2.646688843