N-State (Fuzzy Logic).
Generalization of bool to three or more states.
Fuzzy logic State.
State being either yes, no or unknown.
Tristate: Three-state logic.
https://en.wikipedia.org/wiki/Three-state_logic
https://en.wikipedia.org/wiki/Four-valued_logic
https://en.wikipedia.org/wiki/Many-valued_logic
https://en.wikipedia.org/wiki/Three-valued_logic
https://forum.dlang.org/post/l4gnrc$2glg$1@digitalmars.com
See Source File
N-State (Fuzzy Logic).
Generalization of bool to three or more states.