  Given a directed graph $G$ and a pair of nodes $s$ and $t$, an $s$-$t$ bridge
of $G$ is an edge whose removal breaks all $s$-$t$ paths of $G$. Similarly, an
$s$-$t$ articulation point of $G$ is a node whose removal breaks all $s$-$t$
paths of $G$. Computing the sequence of all $s$-$t$ bridges of $G$ (as well as
the $s$-$t$ articulation points) is a basic graph problem, solvable in linear
time using the classical min-cut algorithm.
  When dealing with cuts of unit size ($s$-$t$ bridges) this algorithm can be
simplified to a single graph traversal from $s$ to $t$ avoiding an arbitrary
$s$-$t$ path, which is interrupted at the $s$-$t$ bridges. Further, the
corresponding proof is also simplified making it independent of the theory of
network flows.
