main =>
  S1 = "abc",
  S2 = "def",
  S1 == S2, % -> false.
  S1 != S2, % -> true.
  S1 @< S2, % -> true. Is S1 lexicographically less than S1?
  S1 @> S2, % -> false.
  to_lowercase(S1) == to_lowercase(S2), % -> false.

  "1234" @> "123",  % -> true. lexical comparison
  "1234" @< 12342222, % -> false. No coersion is done. Numbers are always ordered before strings

  123 < 1234. % -> true   '<' is used only for numbers