# An odd inequality sign

I saw this rather odd symbol of the the greater sign on top of the less sign in my lecture notes. I am wondering if there is a name for this symbol and if signifies 'equal to' as well?

HallsofIvy
Homework Helper
<
>
?

I would interpret that as "is not equal to".

Is it any of these?

$$\lessgtr, \quad \gtrless,\quad \lesseqgtr,\quad \gtreqless,\quad \lesseqqgtr,\quad \gtreqqless$$

Is it any of these?

$$\lessgtr, \quad \gtrless,\quad \lesseqgtr,\quad \gtreqless,\quad \lesseqqgtr,\quad \gtreqqless$$
I'd say it'd probably be the second one.

HallsofIvy
Homework Helper
Again, my best guess is "is not equal to".

It's an abbreviation of < or >, the alternatives being explained or elaborated on nearby.

You could write: a≶b≶c, which means that either a<b<c or a>b>c.
Or you could write something like: |x|=±x if x≷0.
The upper level is one case, the lower level is the other case.

It is rarely used. Different cases are usually put on different lines with braced conditions.