| a. x>=z, where x in S implies z in S, for every element x, y in L |
| b. x=y and y<=z, where x, y in S implies z in S, for every element x, y, z in L |
| c. x<=y<=z, where x, y in S implies z in S, for every element x, y, z in L |
| d. x=y and y>=z, where x, y in S implies z in S, for every element x, y, z in L |
| Answer: x<=y<=z, where x, y in S implies z in S, for every element x, y, z in L |