Who is entitled to enforce?
What is the burden of proof/prima facie case?
The person presenting the instrument for payment need only prove that:
Proof of Signatures → is there a presumption of validity?
Yes. Unless the D specifically denies the validity of any signature in his pleading, its validity is deemed admitted.
What happens if the instrument is lost, destroyed, or stolen?
If a person cannot produce an instrument because it is lost, stolen or destroyed, the person will be entitled to enforce the instrument if she can prove that she was entitled to enforce the instrument when the loss of possession occurred.