Evidence of furnishing or offering or promising to furnish, or of
accepting or offering or promising to accept, a valuable consideration
in compromising or attempting to compromise a claim which was disputed
as to either validity or amount, is not admissible to prove liability
for or invalidity of the claim or its amount. Evidence of conduct or
statements made in compromise negotiations is likewise not admissible.
This rule does not require the exclusion of any evidence otherwise
discoverable merely because it is presented in the course of compromise
negotiations. This rule does not require exclusion when the evidence is
offered for another purpose, such as proving bias or prejudice of a
witness, or negativing a contention of undue delay.
