Movatterモバイル変換

Supertypes:

boolean,symbol,t

Description:

Thetypeboolean contains thesymbolst andnil, which represent true and false, respectively.

See Also:

t (constant variable),nil (constant variable),if,not,complement

Notes:

Conditional operations, such asif, permit the use ofgeneralized booleans, not justbooleans; anynon-nil value, not justt, counts as true for ageneralized boolean. However, as a matter of convention, thesymbolt is considered the canonical value to use even for ageneralized boolean when no better choice presents itself.