Logical fuzzy union and intersection operation calculation circuit

A calculation circuit for selectively calculating fuzzy and non-fuzzy logical operations, comprising:

• a subtracter having first and second inputs that receive first and second input data, respectively, and first and second outputs, the subtracter being structured to produce at the first output a first output datum equal to the difference between the first and second input data;
• and produce at the second output a sign flag indicating whether the difference is positive or negative;
• a first multiplexer having first and second data inputs, a control input, and an output, the first and second data inputs receiving the first and second input data, respectively;
• the control input being coupled to the second output of the subtracter, and the first multiplexer being structured to supply at the output of the first multiplexer a one of the first and second input data which is selected depending on the sign flag;
• and
• a second multiplexer having a first and a second data inputs, a control input, and an output, the first and second data inputs being coupled to the first output of the subtracter and the output of the first multiplexer, respectively.

A method of performing logical fuzzy union and intersection operations on first and second inputs, the method being practiced on a computer, the method comprising:

• determining a difference between the first and second inputs, resulting in a difference value corresponding to the difference and a sign flag indicating a sign of the difference;
• comparing the sign flag with a first selection signal having a first value if the fuzzy logical union operation is selected and a second value if the logical fuzzy intersection operation is selected, the comparing resulting in second selection signal having a first level when the sign flag and the first selection signal comply with a predetermined relation and a second level when the sign flag and the first selection signal do not comply with the predetermined relation;
• and
• selecting as a first output one of the first and second inputs depending on whether the second selection signal has the first level or the second level.