> > But I like the idea of "erroring" to opposite sides. What
> > about the center column?

I added erroring to the left on the left hand side and erroring
to the right on the right hand side to my code. Looks nice.

 left = !right = cellnr > row.length/2

Sometime Ruby makes me smile. I mean, left isn't right, is it?

If I run it in $DEBUG mode, its output looks like the pictures
below. It clearly shows "cells", "seperators" and "margins".

gegroet,
Erik V. - http://www.erikveen.dds.nl/

----------------------------------------------------------------

 $ pascaltriangle 8
 >>>>>>>>>>>>>.1.<<<<<<<<<<<<<
 >>>>>>>>>>>.1. .1.<<<<<<<<<<<
 >>>>>>>>>.1. .2. .1.<<<<<<<<<
 >>>>>>>.1. .3. .3. .1.<<<<<<<
 >>>>>.1. .4. .6. .4. .1.<<<<<
 >>>.1. .5. .10 10. .5. .1.<<<
 >.1. .6. .15 20. 15. .6. .1.<
 1. .7. .21 .35 35. 21. .7. .1

 $ pascaltriangle 12
 >>>>>>>>>>>>>>>>>>>>>.1.<<<<<<<<<<<<<<<<<<<<<
 >>>>>>>>>>>>>>>>>>>.1. .1.<<<<<<<<<<<<<<<<<<<
 >>>>>>>>>>>>>>>>>.1. .2. .1.<<<<<<<<<<<<<<<<<
 >>>>>>>>>>>>>>>.1. .3. .3. .1.<<<<<<<<<<<<<<<
 >>>>>>>>>>>>>.1. .4. .6. .4. .1.<<<<<<<<<<<<<
 >>>>>>>>>>>.1. .5. .10 10. .5. .1.<<<<<<<<<<<
 >>>>>>>>>.1. .6. .15 20. 15. .6. .1.<<<<<<<<<
 >>>>>>>.1. .7. .21 .35 35. 21. .7. .1.<<<<<<<
 >>>>>.1. .8. .28 .56 70. 56. 28. .8. .1.<<<<<
 >>>.1. .9. .36 .84 126 126 84. 36. .9. .1.<<<
 >.1. .10 .45 120 210 252 210 120 45. 10. .1.<
 1. .11 .55 165 330 462 462 330 165 55. 11. .1

----------------------------------------------------------------