proc logic a b .
if a = 1 and b = 1
r1 = 1
.
if a = 1 or b = 1
r2 = 1
if a = 0
r3 = 1
print r1 & " " & r2 & " " & r3
logic 0 0
logic 0 1
logic 1 0
logic 1 1
