This function checks whether an incomplete block design is proper or not. Incidence
matrix of the design is to be supplied as input to the function. If the design is proper, it returns
a value of 1 else it returns 0.
# NOT RUN {N=matrix(c(1,0,0,0,1,0,1,0,0,0,1,0,1,1,0,0,1,0,1,1,0,1,0,1,1,0,0,0,0,1,1,0,0,0,1,1,1,0,
0,0,1,0,0,1,0,1,1,0,0),nrow=7,byrow=TRUE)
is.proper(N)
# }