A line has start and end. Let's call them A and B. And sometimes the line is "valid" (by my Kata rules) in one direction only. e.g from A-to-B, or from B-to-A, but not both at the same time.
But being valid in one direction only is sufficient to call the whole line "valid".
So Sometimes a line may be valid in one direction but not the other. Such a line is still considered valid. means:
valid A-to-B, but not B-to-A ==> line is valid
not valid A-to-B, but valid B-to-A ==> line is valid
valid A-to-B, and valid B-to-A ==> line is valid
not valid A-to-B, and not valid B-to-A ==> line is NOT valid
A line has start and end. Let's call them A and B. And sometimes the line is "valid" (by my Kata rules) in one direction only. e.g from A-to-B, or from B-to-A, but not both at the same time.
But being valid in one direction only is sufficient to call the whole line "valid".
So
Sometimes a line may be valid in one direction but not the other. Such a line is still considered valid.means: