Ab=cd w divergence

hello

i am learning divergence by a very skilled trader and is working well, however he is starting to use abcd with continuation divergence, can anyone shed some light on this? and maybe post some examples? I cant actually find anything in google on it please help

He’s probably just seeing if there is a divergence at the A and C points with whatever oscillator or indicators he uses compared to the price action, then going for the continuation on the CD leg.