hunt the LaTeX symbol no more

So there you are, writing some maths in LaTeX, and you need that symbol that's a tilde on top of an equals sign:

but you can't remember the markup.  So, it's off to Google: "LaTeX mathematical symbols".  Up pops "The Comprehensive LaTeX Symbol List", a 178 page PDF.  Scan through section 3, "mathematical sysmbols", and eventually find:

Squint at the screen.  Zoom in.  Yes, it's \cong.  Carry on typing.  Then you need another symbol...

Surely there's an easier way?  Well, I've just stumbled across a marvellous website that gets rid of the need to scan through hundered of pages of tiny symbols.  Meet Detexify - LaTeX symbol classifier:

Do what it says -- draw here!

It takes a few seconds, but then a bunch of symbols appears -- including \cong. Perfect!

My symbol drawing is dreadful here, because I'm using a mouse, and using it right-handed at that.  But that doesn't matter, because the system is very forgiving and provides a range of possibilities "similar" to the crude sketch:

If you know what it looks like, you can find it.

Brilliant.