Looks like your coordinates are different to normal western ones with no i and 1 at the bottom, I suppose you mean this
a (which is L5 in our coordinate system, the bizarre
b is L5 in the system in which 79 is r8)?
$$Bcm79
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . . . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X , . . . . . , X X . |
$$ | . . . O O . . O c . . b . . X X O . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . X O 1 . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . a . W . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Bcm79
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . . . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X , . . . . . , X X . |
$$ | . . . O O . . O c . . b . . X X O . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . X O 1 . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . a . W . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Assuming so: any answer to white's marked stone is a good exchange for him, so I think fighting spirit partly explains why tenuki. He did play L5 soon though, after the exchange of 79 for white
c. I guess those can be thought of as big moves miai, black could make top side points like this (but also helps white make left middle points):
$$Bcm78
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . 1 . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X 3 . . . . . , X X . |
$$ | . . . O O . . O 2 4 5 7 . . X X O . . |
$$ | . . . . . . . . . . 6 . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . . . O . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Bcm78
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . 1 . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X 3 . . . . . , X X . |
$$ | . . . O O . . O 2 4 5 7 . . X X O . . |
$$ | . . . . . . . . . . 6 . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . . . O . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Also s12, whilst looking slow, does set up the r8 invasion, which has the potential to unsettle white. As we saw in the game white had to be mindful of this when black cut and ran out the right middle, for example defending with 108 and 116 (though these defences weren't of course pure defence but had future attacking aims too as we saw when Takao cut off the tail). It's a really hard position though, so whilst I can reasonably confidently say this move or that move has this good thing or that bad thing, combining them all and making a judgement of what is the best move is too hard for me.
If white jumped again, what would black do? Given Takao's move, I guess somewhere around there?
$$Bcm79
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . a . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X , . . . . . , X X . |
$$ | . . . O O . . O b . . . . . X X O . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . c . . . . . . . . X O 1 . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . 2 . O . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Bcm79
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . a . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X , . . . . . , X X . |
$$ | . . . O O . . O b . . . . . X X O . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . c . . . . . . . . X O 1 . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . X X X X . . . . . . . . . O . . . |
$$ | . . X . . X O . . . . . . . . . O . . |
$$ | . O X X . X O . . . 2 . O . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Full game below for reference: