A inj B
For finite sets \(A\) and \(B\), \(\;A \text{ inj } B\) is equivalent to:
An injective function from \(A \) to \(B \) or a surjective relation from \(B \) to \(A \) do not guarantee \(A \text{ inj } B\).
For finite sets \(A\) and \(B\), \(\;A \text{ inj } B\) is equivalent to: