results2 <- list()
for (j in c(1:14)) {
  for (i in c(1:14)) {
    results2[["SS"]][[j]][[i]] <- list(which(Diff11[,j] == 0 & Diff22[,i] == 0, arr.ind =TRUE))
  }
}
why it gives me Error in *tmp*[[j]] : subscript out of bounds, when both Diff11 and Diff22 are tbl_df with 14 columns?
 
    