Learn the Gemara from after the Mishna until the two dots.
Questions:
A vertical fence that has gaps is a valid mechitza if it is עמוד מרובה as the gaps are considered פתחים – points of access. What is the logic to entertain allowing horizontal gaps?
Our Gemara is uncertain whether we consider עומד מרובה משתי רוחות a valid mechitza. How is this consistent with the גמרא דף י עמוד ב which seems to conclude it is a valid mechitza?
The Gemara concludes that the halacha is in accordance with רב פפא that פרוץ כעומד מותר. Is there a difference in the concept of עומד מרובה to פרוץ כעומד מותר?