Adjacent (隣接する Rinsetsu suru) is a term that refer to the condition when two Z/X are positioned vertically or horizontally next to each other.
Comprehensive Rules
1017 Adjacent
1017.1 "Adjacent" means that if a Z/X is on a Square that is vertically or horizontally adjoined to another Z/X, those Z/X are treated as a set of adjacent Z/X. However, Z/X on Square diagonally adjoined to another Z/X are not treated as adjacent Z/X.
1017.1a If 3 Z/X are laid in a single line, the left and center Z/X, as well as the center and right Z/X, are each treated as one set of adjacent Z/X.
