  We study intrinsic coherence in the tripartite process to unambiguously
discriminate two nonorthogonal states of a qubit, entangled with another one,
and assisted by an auxiliary system. The optimal success probability is found
to be benefited by initial intrinsic coherence, but no extra one is required.
The transformations among different contributions of intrinsic coherence are
necessary in this procedure, which increase with the overlap between the states
to recognize. Such state discrimination is a key step of the probabilistic
teleportation protocol. Entanglement of the quantum channel decreases the
coherence characterizing the reliance on an ancilla.
