∥
Symbol  Format  Data 

∥  Code Point 
U+2225 
TeX 
\parallel 

SVG 
In geometry, the parallel symbol is used to denote two lines that are parallel to each other. Typically the parallel symbol is used in an expression like this:
In plain language, this means that the line is parallel to the line . Read more…
The not parallel symbol is used to state that two lines are not parallel.
Parallel lines are denoted by the parallel symbol placed between the notation of the two lines. A line is denoted by the start and end letter with a line over top.