/* ch 13 2 has abc cde also abde confounded */
data gen01;
do i=1 to 64;
if _n_>65 then goto over;
a=0;
b=0;
c=0;
d=0;
e=0;
f=0;
f=mod(i-1,2);
ej=mod(i-1,4);
dj=mod(i-1,8);
cj=mod(i-1,16);
bj=mod(i-1,32);
aj=mod(i-1,64);
if aj/32 ge 1 then a=1;
if bj/16 ge 1 then b=1;
if cj/8 ge 1 then c=1;
if dj/4 ge 1 then d=1;
if ej/2 ge 1 then e=1;
output;
end;
over: i=0;
data cells; set gen01;
keep a b c d e f;
data contrst; set cells;
a1=1;
b1=1;
c1=1;
d1=1;
e1=1;
f1=1;
if a=0 then a1=-1;
if b=0 then b1=-1;
if c=0 then c1=-1;
if d=0 then d1=-1;
if e=0 then e1=-1;
if f=0 then f1=-1;
data confnd; set contrst;
block1=mod(a+b+c,2);
block2=mod(c+d+e,2);
proc print;
/* ch 13 2 */
run;
quit;