We acknowledge the possible support received from:

• Vicerrectorado de Investigación y Transferencia.
• Departamento de Matemáticas, University of Cádiz (Spain).
• Consejo Social de la Universidad de Cádiz (Spain).
• Programa de doctorado interuniversitario en Matemáticas.
• Mathematics for Computational Intelligence Systems (M·CIS), University of Cádiz (Spain).
• International Fuzzy Systems Association (IFSA).
• European Society for Fuzzy Logic and Technology (EUSFLAT).