options ls=75;
data one;
   input a $ b block y;
   cards;
0  0.25  1  30.7
0  0.25  2  24.7
0  0.25  3  16.9
0  0.50  1  22.7
0  0.50  2  15.0
0  0.50  3  13.6
0  1.00  1  23.0
0  1.00  2  17.1
0  1.00  3  15.2
1  0.25  1  28.4
1  0.25  2  19.6
1  0.25  3  16.2
1  0.50  1  20.1
1  0.50  2  16.8
1  0.50  3  15.1
1  1.00  1  18.4
1  1.00  2  13.9
1  1.00  3  14.3
;
run;
proc mixed method=type3;
   class a b block;
   model y=a|b;
   random block;
   estimate "a_hi - a_lo" a -1 1/cl; 
   lsmeans b/diffs adj=tukey;
run;