(specially concurring).
The second part of defendant’s first point of error is as follows:
“The trial court abused its discretion by entering judgment for the plaintiff when the plaintiff did not prove that it attempted to mitigate its damages.”
Under the doctrine of “avoidable consequences” the injured person has the duty to use reasonable diligence to mitigate damages incurred either from tort or breach of contract. Mitchell v. James, 47 N.M. 169, 138 P.2d 522 (1943); Rutledge v. Johnson, 81 N.M. 217, 465 P.2d 274 (1970).
Mitigation of damages is an affirmative defense and the burden is on the defendant to show that the plaintiff, by the exercise of reasonable diligence, could have minimized damages. Kelty v. Best Cabs, Inc., 206 Kan. 654, 481 P.2d 980 (1971); Comfort Homes, Inc., v. Peterson, 549 P.2d 1087 (Colo.App.1976). Under a general denial defendant can question and counter plaintiff’s proof of damages, but he cannot seek to show what the plaintiff could have done in the exercise of reasonable diligence to minimize his damages further. Defendant had the burden of affirmatively pleading mitigation of damages and of proving that the plaintiff could have minimized damages by the exercise of reasonable diligence. He did neither.
I agree that plaintiff’s contract with Oliver Gallegos was not void for lack of mutuality of obligation. Their agreement, although entitled “Exclusive Concession Lease” was in my opinion one to provide various vending and amusement machines and equipment, that is, a requirements contract. Paragraph 1 reads in part as follows: “That this lease . . . giving and granting to the LESSEE the right . of installing . . . electrical phonographs, amusement devices, and cigarette machines, on the above described premises as the LESSEE may from time to time determine to be required to best fill the needs and requirements for such machines at the above described premises. . During the term of this lease . . . .”
“ ‘Mutuality of contract’ means that obligation rests on each party to do or permit doing of something in consideration of other party’s act or promise. . . .” Black’s Law Dictionary (Rev. 4th Ed., 1968).
“It is now beyond question that contracts for requirements do not lack mutuality and are enforceable. In every case it is the reasonable expectation by both parties that there will be requirements on which the bargain is grounded.” Locke v. United States, 283 F.2d 521, 151 Ct.Cl. 262 (1960). See, Uniform Commercial Code, § 50A-2-306, N.M.S.A.1953 (Repl. Vol. 8, pt. 1). Also see, Gruschus v. C. R. Davis Contracting Company, 75 N.M. 649, 409 P.2d 500 (1965).