The fuzzy argument is used to derive a trueness level from a numeric value (either simple data link or calculated data link) using a fuzzy curve. The value returned is completely dependent on the shape of the fuzzy curve.
The fuzzy argument's fuzzy curve is defined with of any number of coordinate (x,y) pairs where the x value is the input and the y value is the output.
Whereas the crisp argument evaluates to only true, false, or undetermined; the fuzzy argument is less sensitive to minor changes in data and allows interpreting the data in graceful transitions (“shades of gray”) rather than abruptly (“black and white”).