Tung,
If in Nemeth Code you have a long dash followed by a variable, then a space should follow the long dash. (See §42 of the Nemeth Code.)
So, for
y = __x + __
the appropriate transcription would be
⠽⠀⠨⠅⠀⠤⠤⠤⠤⠀⠭⠬⠀⠤⠤⠤⠤
Thank you for you question.
Sincerely,
Kyle
