Sorry if this is a repost - I am almost sure my last post did not reached out. Rob Stewart wrote:

meaning "arbitrary value." However, "indeterminate" leaves no doubt as to the meaning of the value and doesn't depend upon one's experience with electronics. Another possibility would be

I agree. Although I see the highest potential of the library in EDA applications, the meaning of the value should not depend on any problem domain - like electronics. I guess I was little bit biased here by my problem domain.

As I've already rejected the "x" notion, that leaves "unknown_bool" or, by extension, "indeterminate_bool." While these names suggest that there is an unknown or indeterminate Boolean value, they don't suggest to me a type that includes true, false, *and* unknown/indeterminate. "tribool," OTOH,

I disagree. IMHO, The name unknown_bool hints that in addition to the 2 traditional values of bool, there is also an unknown bool. I am not a native user of the English language, but this is what the name unknown_bool hints *me*. Haim -- _____________________________________________________ Haim Cohen Software Engineer haim.cohen@analog.com / haimcohen2002@hotmail.com Analog Devices