helpA Mamdani controller has the following rule base:

if error is negative and and change of error is negative then control action is big

if error is zero and and change of error is negative then control action is big

if error is zero and and change of error is zero then control action is medium

if error is zero and and change of error is positive then control action is medium

if error is positive and and change of error is zero then control action is small

if error is positive and and change of error is positive then control action is small

The linguistic variables are defined as follows:

Error:

Change of error:

Control Action:

I

a$)$ Using max$-$min composition, calculate the fuzzy set of control, when:

i$)$ error $=2$ and change of error $=4.$

ii$)$ error $=-2$ and change of error $=-2.$