In A’s suit against B for the price of delivered goods, witness C says he delivered them. Under BSA…

Section 158 illustration (a) expressly treats the inconsistent former statement as "Admissible to impeach C's credit, subject to applicable contradiction procedure"; section 158(c) concerns contradictions of qualifying parts of the testimony. It is neither "Inadmissible merely because it is C's own earlier statement" nor "Admissible only if C first agrees that his present evidence is false", and "Conclusive proof of non-delivery without assessment of the evidence" is wrong because admission for this purpose does not automatically establish the truth of the earlier version or conclusively decide delivery.