1. Question: Why would the Har Tzvi say that writing one letter on copy paper/carbon paper which will copy itself on the next page is not considered writing two letters on Shabbos but erasing the bridge on the letter ches, turning it into two zayins is considered writing two letters on shabbos?
Background:
A. The Tilale Sadeh hold these two cases are comparable to each other so on the contrary by the ches which the bridge was erased it should not be as bad because you didn’t even write one letter and nevertheless you are liable because we go by the result which was creating two zayins, so all the more so if you wrote one letter and the letter was copied on the next page you should be liable for writing two letter, so why is the Har Tzvi unsure of the comparison?
B. One is only liable for writing on Shabbos if two letters were written.
Answer: Granted by erasing the bridge on the ches which creates two zayins one is liable on shabbos because you don’t have to literally write two letters, if one creates two letters which ever way one is liable because he actually created two zayins which were not there until now, it was just made all at once when the bridge of the ches was erased. But when writing one letter on this copy paper only one letter is really being written it’s just an impression of it is made on the next page, meaning two letters weren’t really written, rather only one was written and imposed on the next page so really only one letter was written so not liable for writing on shabbos. [/exapnd]