DIM x(9), y(9)

      FOR I% = 0 TO 9
        READ x(I%), y(I%)
      NEXT

      min = 1E30
      FOR I% = 0 TO 8
        FOR J% = I%+1 TO 9
          dsq = (x(I%) - x(J%))^2 + (y(I%) - y(J%))^2
          IF dsq < min min = dsq : mini% = I% : minj% = J%
        NEXT
      NEXT I%
      PRINT "Closest pair is ";mini% " and ";minj% " at distance "; SQR(min)
      END

      DATA  0.654682, 0.925557
      DATA  0.409382, 0.619391
      DATA  0.891663, 0.888594
      DATA  0.716629, 0.996200
      DATA  0.477721, 0.946355
      DATA  0.925092, 0.818220
      DATA  0.624291, 0.142924
      DATA  0.211332, 0.221507
      DATA  0.293786, 0.691701
      DATA  0.839186, 0.728260