where x = (x1, x2,. . ., xn,) is a vector of non-fuzzy decision variables,
c˜j is coefficient in objective; a˜ij, b˜i are fuzzy coefficients in
constraints. Here, i is the number of constraints and j is the number
of variables. Formula (1a) is the objective function in the optimal
framework. Formula (1b) shows that the credibility of constraint