The menace of doubled cannons

The following snippet of a xiangqi game ( Red to move ) demonstrates clearly the power of doubled cannons. 

1. C8+2  C4+6 ( Not obvious but necessary step to protect the backrank elephant. )  2. R5+1 ( getting rid of the defender of the kindred piece. ) C4=3 ( using the pawn as a mount to protect the elephant from afar. ) 

3. R8-6 ( Once the pawn moves sideways, this rook can assume the rook of the defender of the elephant . ) 

...E5+7 ( Now both the cannon and the rook can't protect the elephant any more and the checkmate with doubled cannons can't be avoided. ) 

Sorry, 3. R8-6 seems to be an invalid move or notation. Or what am I missing? I don't see any red rook on red's 8th file.

I think after 2. ... C4=3 the next move of red was P7+1.

There is also this place:

https://www.chess.com/groups/forum/xiangqi

Sorry for making a mistake here: It should be 3. P7+1  R8-6 4. E5+7 . It is the omission of the pawn move that causes so much trouble to you.