Moving average cross over

I think you need to be more specific about what "intersect" means.

You need to list out which MAs cross which, and in what direction. For instance, does the falling 21 cross the falling 50? or the rising 50? or the rising 21 the rising 50, etc. Once you spell it out in plain english the coding will be easy.

...

and [ema(8, close) x ema(21, close)]
and [ema(8, close) x ema(50, close)]