options nocenter ls=75;

data example1;
input trt y @@;
cards;
1 1.90 1 1.80 1 1.54 1 4.10 1 1.89 
2 0.82 2 3.36 2 1.64 2 1.74 2 1.21 
3 5.33 3 4.84 3 5.26 3 4.92 3 6.07 
4 3.08 4 1.42 4 4.54 4 1.25 4 2.57
;

proc glm;
 class trt;
 model y=trt;
 contrast 'L' trt -1 1 -1 1;
 contrast 'E' trt -1 -1 1 1;
 contrast 'interaction' trt 1 -1 -1 1;

data twoway;
 set example1;
 L=0; E=0;
 if trt=3 | trt=4 then E=1;
 if trt=2 | trt=4 then L=1;

proc glm;
 class E L;
 model y=E L E*L;
 lsmeans L*E / stderr tdiff slice=E;

proc glm;
 class E L;
 model y=E L E*L;
 random E L E*L / test;

proc glm;
 class E L;
 model y=E L E*L;
 random L E*L / test;
 lsmeans E / tdiff stderr;
 lsmeans E / tdiff stderr E=E*L;

proc mixed;
 class E L;
 model y=E;
 random L E*L;
 lsmeans E / diff;
run;
quit;