You can replace slanted parallel symbol as unicode ⫽ (U+2AFD, Double Solidus Operator)
I had to insert parallel symbol with using MathJax. Official unicode symbol of the "parallel" and "not parallel" signs have codepoints U+2225 (∥) and U+2226 (∦) However, what I had to make was a slanted parallel symbol, similar as // (two slashes). existing solutions offer using some special packages, but I cannot use any special package in my work. I tried to find another unicode symbol as simi..