Let \(A\), \(B\) and \(C\) be nonempty sets and let \(f: A \to B\) and \(g: B \to C\). \(\bullet\) For every \(a \in A\) and every \(b, c \in B\), if \((a, b) \in f\) and \((a, c) \in f\), then \(b = ...Let \(A\), \(B\) and \(C\) be nonempty sets and let \(f: A \to B\) and \(g: B \to C\). \(\bullet\) For every \(a \in A\) and every \(b, c \in B\), if \((a, b) \in f\) and \((a, c) \in f\), then \(b = c\). Then \(f^{-1}: B \to A\) is a function, and for every \(a \in A\) and \(b \in B\), Let \(f: S \to T\) be a function and let \(A\( be a subset of \(S\) and let \(C\) be a subset of \(T\).
