tim wrote on 11/18/22 at 14:30:12:

No author can consider every possible move, always at some point the reader will be on their own and have to just play chess.

tim wrote on 11/18/22 at 14:30:12:

No. You won't be able to transpose back into the other stuff which involves ...Ng8-f6 and ...e7-e6.

Since 4...c6? 5.cxd5 cxd5 is an Exchange Slav in a bad version for black, and 4...e6?? is out of the question, just play 4...dxc4 and let the engine guide you on how to follow up. But at some point you might want to play differently than the engine's suggestion. The engine will try to keep the pawn, but for a human it's often better to give the pawn back at the right moment, to get the rest of the pieces out. The trick is figuring out which is the right moment.