/* all 6 comparison operators (last is "not equal") */
block(
   [a: read("a?"), b: read("b?")],
   if a < b  then print(a, "<",  b),
   if a <= b then print(a, "<=", b),
   if a > b  then print(a, ">",  b),
   if a >= b then print(a, ">=", b),
   if a = b  then print(a, "=",  b),
   if a # b  then print(a, "#",  b))$