infinite-valued logic
a system of logic that differs from classical logic, which permits only two truth categories to be assigned to a proposition (true or false), by allowing for multiple categories or degrees of truthfulness. For example, whereas the statement Smith is a professor is either true or false, the statement Smith is depressed might have varying degrees of truthfulness. Thus, the intersection of the categories “Smith” and “depressed” has “fuzzy” as opposed to “crisp” boundaries. Infinite-valued logic is related to fuzzy logic. See also bivalence.