This function checks that the enviromnemt variable is internally consistent.
Environment variable obtained from fm.Init(n).
The ouput is TRUE or FALSE.
Gleb Beliakov, Andrei Kelarev, Quan Vu, Deakin University
 http://www.deakin.edu.au/~gleb/fmtools.html  H.Q. Vu, G. Beliakov, G. Li, 2014, A choquet integral toolbox and its application in customer preference analysis, in Data mining applications with R, Elsevier Inc., Waltham, MA., pp.247-272.