摘要: Most of the conventional tools for formal modeling, reasoning, and computing are hard, deterministic, precise. Thereby hard implies unambiguity that is, yes-or-no rather than more-or-less. In traditional bivalent logic, example, a statement can be true or false—and nothing in-between. Precision assumes parameter model typifies precisely features real system has been modeled. Usually, precision also is doubtless, it covers no ambiguities (Zimmermann, 2001).