It is not just 'light and flexible', it is 'making light flexible shape' --> ~= 'coping'
Kirby: This may be attempt at humour, in which case forgive me but it has gone right over my head. I also have no idea what your (?pseudo) mathematical symbols are supposed to mean.
But it occurs to me that you may be too young to be properly aware of the full background. I have expounded it here before and don't want to repeat it all again, though perhaps you could redirect your fossicking powers to find and re-quote that instead. But the highlights are as follows.
Around 50 years ago the notion of sabaki in the west was one that could be described in the 1992 edition of The Go Player's Almanac as "making light, flexible shape in order to save a group" (page 195).
That inadequate definition, which predates the 1992 Go Almanac has, unfortunately, got stuck in the foot of go like a pernicious verruca. It does at least acknowledge that sabaki is a verbal noun, but matters have been made worse by other people making the equation simply "sabaki = light and flexible shape."
The Go Almanac version was corrected in the 2001 edition (page 360) to "managing a weak group of stones so that it does not become a burden, e.g. by giving it a viable or flexible shape, or sacrificing part or all of it." This is correct. However, the inclusion of a single example citing flexible shape is a nuisance, because people used to hearing the older, incorrect version, where flexible shape is dominant, didn't register properly that this was a major change. It would have been better if the new definition had given more examples, including, say, "heavy" sabaki. My campaign (for want of a better word) has been to try to widen the range of examples to marry with normal Japanese usage by pros. I am NOT precluding cases of sabaki where moves are light and flexible. I am just saying it is wrong to say "fruit = apple" (even if you could get away with saying "apple = fruit"). We should be saying "fruit = apple, pear, orange, banana, tomato, etc etc etc etc).