The image shows two formulas referring to the first set of lines. Does the reference to in the image refer to the second set of parallel lines? If so, apparently I was able to understand the article, or I wouldn't have formed the question; though I did scratch my head a bit at first.--Cyberchip (talk) 17:09, 6 October 2015 (UTC)
- Yes, the spacing between the first set of lines is p, and the spacing between the second set it p+δp. --Lasunncty (talk) 18:46, 7 October 2015 (UTC)