Reply To: Sets of numbers – R, N, Z
Yes, that attachment helps a lot. You are correct that your print is using the "double struck" or "blackboard bold" typeface for letters that refer to sets of numbers (e.g. ℝ for real numbers, ℤ for integers, ℕ for natural numbers).
In a transcription using Nemeth within UEB, in instances like you describe, it is considered best practice to switch into Nemeth Code for double struck letters wherever they appear and to use the Nemeth Code script typeface for such double struck typeface (with the typeface substitution explained in a transcriber's note).
Please let me direct you to Lesson 7 of the Provisional Revised Nemeth Course Manual, posted by NFB [especially 7.10 and Example 7.5-1, including the commentary before it] for more discussion and examples.
–Kyle