dissenting in part, with whom THOMAS, Justice joins.
I concur with the majority in sustaining the judgment of the district court fixing the sum due from ARCO and Certified to Rissler1 but must dissent from that part of the opinion requiring the inclusion of interest. The majority present a well structured argument, the basis of which is the long and well established rule of this court that claims which are readily calculable by simple mathematical computation2 from the face of the contract3 are claims upon which prejudgment interest is to be included in the judgment as a matter of law.4 They find the parameters for computation on the face of an oral contract which they find was entered into between Rissler and ARCO. This is done by a process of interpretation of the evidence and the jury’s verdict, which is unacceptable to me.
As I read the opinion, it holds that although the evidence was conflicting as to the negotiations and arrangements between ARCO, Certified and Rissler, this court is entitled to weigh that evidence and conclude that “ARCO dealt directly with Ris-sler and instructed Rissler to proceed on the basis of its quoted figure of $1.75 per square yard, three inches thick. An oral contract was thus formed.” Using this contract standard agreed upon by Rissler and ARCO of $1.75 per square yard, three inches thick, it then becomes a matter of rudimentary arithmetic to compute the amount due. This results in a liquidated figure “which should bear interest from the date due.”
My own examination of the evidence leaves me in doubt that an actual oral contract existed between ARCO and Rissler for the performance of the paving work upon an agreed compensation and were it material to the position which I take I might well disagree. However, throughout the pleading, pretrial and trial stages of the proceedings and upon appeal to this court Rissler has continued to present alternative claims: (1) that either there was an express contract for the furnishing of service and materials at an agreed price permitting appli*36cation of the contract prices to the work done; or (2) that it did the work with the full knowledge and acquiescence of ARCO and for that reason was entitled to recover the reasonable value of the service and materials furnished, as established by independent evidence, which recovery is usually referred to in the pleadings and arguments as quantum meruit. If it is only the reasonable value of the service and materials that is recoverable, and even if the jury finds such reasonable value to be $1.75 per square yard, 3" deep, it nevertheless follows that the amount of the claim was not liquidated prior to the suit and could not be so liquidated until the trier of the fact had determined such reasonable value.
I think this qualification is clearly recognized by authorities cited by the majority, particularly those from Washington and the Ninth Circuit. Mall Tool Company v. Far West Equipment Company, 45 Wash.2d 158, 273 P.2d 652, 654 (1954); Paduano v. J. C. Boespflug Construction Company, 66 Wash.2d 527, 403 P.2d 841, 845 (1965), and Elte, Inc. v. S. S. Mullen, Inc., 469 F.2d 1127, 1133 (9 Cir. 1972), reh. denied, apply a definition of a liquidated claim as stated in McCormick on Damages § 54, p. 213 as one where “the evidence furnishes data which, if believed, makes it possible to compute the amount with exactness, without reliance upon opinion or discretion.” (Emphasis added) The qualification is clearly applied in Hopkins v. Ulvestad, 46 Wash.2d 514, 282 P.2d 806, 810 (1955):
“ * * * This is not a case involving a promise to pay for labor and material at an agreed rate and thus capable of being referred to as a ‘liquidated’ claim. It is rather a case involving an implied promise to pay at a reasonable rate for labor and material furnished, and hence is an ‘unliquidated’ claim. * * * ”
No one questions that Rissler was entitled to payment in some amount from someone for the work performed by it, but not only did it introduce evidence tending to justify recovery in contract, it also introduced expert testimony designed to establish the reasonable value of the work done by it. A specific instruction on quantum meruit was objected to only by ARCO and no party contends in this court that the instruction as such did not represent a correct statement of the law. While continuing to claim that the jury could properly have found an oral contract and based its verdict thereon, Rissler has in no way abandoned its previous claims to recovery of the reasonable value of its work. The majority’s conclusion that the jury found that there was an oral contract fixing the price of the work, rather than that Rissler was entitled to the reasonable value thereof, is in my opinion unjustified.
In the first reported case of the Supreme Court of Wyoming Territory, Western Union Telegraph Company v. Monseau, 1 Wyo. 17, 19 (1870) it was said:
“ * * * [I]f there is evidence proper to be submitted to a jury on the issue before them, it is their province to weigh it; and it must be a very clear case, appealing very strongly to the conscience of the court, to induce or permit us to interfere with their decision. It is not sufficient that another jury might probably arrive at a different conclusion, nor that the court should be entirely satisfied with the verdict; if there is evidence proper for them to consider and tending to prove the issue presented, we must be satisfied with their judgment, unless it is made to appear that their judgment has been unfairly exercised.”
This reluctance to weigh evidence has continued throughout the court’s history and in Culver v. Sekulich, 80 Wyo. 437, 344 P.2d 146, 156 (1959), Mr. Justice Parker, speaking for the court, said:
“ * * * It is the function of an appellate court to ascertain whether or not there was substantial evidence upon which the trier of fact could base its opinion if it believed the testimony. It is not for us to evaluate the evidence that was presented.”,
and shortly thereafter in Neal v. Wailes, 346 P.2d 132, 134 (Wyo.1959) Mr. Chief Justice Blume expressed it this way:
*37“ * * * It is not proper for this court in a case tried before a jury to exercise any authority beyond the periphery of its ordinary power but leave to the jury the function of finding the facts as heretofore exercised under the rules of common law, reconciling the conflict in the evidence, and drawing its own inference, if more than one inference is permissible. $ jfc }fc
If, on conflicting evidence, it is not for us to say what view of the evidence the jury should have accepted, how can we logically hold that where two alternative theories are available to and actively pursued by the prevailing party, we may weigh the evidence and conclude as a matter of law that the jury has found the facts under one theory? The rule that “a general verdict in favor of a party includes a finding on every material, necessary, and issuable fact which has been submitted to the jury,” O'Brien v. General Motors Acceptance Corporation, 362 P.2d 455, 457 (Wyo.1961), is not helpful because it is only necessary facts that are to be so considered as found and in the case at bar a finding of rendition of valuable services and the reasonable value thereof is all that is necessary to sustain the verdict.
I find no cases directly in point on the subject, but in Schultheiss v. Los Angeles Ry. Corporation, 11 Cal.App.2d 525, 54 P.2d 49, 50 (1936) it was said:
“It might also be here observed that a reading of the transcript of the evidence in this case clearly shows that the verdict of the jury herein could as well have been based upon a total lack of negligence on the part of respondent as upon contributory negligence upon the part of the appellant through a violation of the ordinance in question. In such a situation appellate courts will not look behind the verdict in an attempt to ascertain the theory adopted by the jury.”
In Lo Galbo v. Columbia Casualty Company, 234 App.Div. 510, 255 N.Y.S. 502, 504 (1932) judgment had been obtained against a person insured by the defendant insurance company, and it was not clear from the judgment whether the recovery had been based upon negligent maintenance of certain property or upon violation of an applicable city ordinance. In the one instance the indemnifying insuror was liable; in the second it was not. The court said:
“The plaintiff having invoked two grounds of negligence, the general verdict in his favor may not be construed to have been based upon one ground only— the manner of piling the beams.”
Summary judgment in favor of the injured party against the insuring company was reversed and the cause remanded for a factual trial.
Since we are not ordinarily the trier of the facts, I do not think that we can assume that burden for the sole purpose of permitting recovery of interest. We have expressly rejected ARCO’s objections relative to the failure of the trial court to make the jury indicate the basis of its verdict. I do not think that it then lies within our province to say upon which of two alternative theories, both favorable to the prevailing party and supported by substantial evidence, the jury has found in favor of that party, any more than we are permitted to weigh conflicting evidence and reach a determination thereon contrary to the jury’s.
I would affirm the judgment in all respects.
. Parties are referred to as in the majority opinion.
. Zitterkopf v. Roussalis, 546 P.2d 436, 439 (Wyo.1976); Mader v. James, 546 P.2d 190, 195 (Wyo. 1976), reh. denied. The principle appears first to have been enunciated in the denial for rehearing in Kuhn v. McKay, 7 Wyo. 42, 65, 51 P. 205, 206 (1897), and has been applied in numerous cases as cited in the majority opinion.
. Chandler-Simpson, Inc. v. Gorrell, 464 P.2d 849, 853 (Wyo.1970) appears to be the only Wyoming decision referring to the face of the contract. Kuhn, supra n. 2, found the basis for computation in an established market price; others have recognized that this was a valid basis but found that there was no established market price, e. g., Johnson v. Hanover Fire Insurance Company, 59 Wyo. 120, 137, 137 P.2d 615, 619-620 (1943).
. Only for purposes of this dissent do I accept this rule. I am in complete agreement with the majority that the whole matter of prejudgment interest deserves extensive consideration by this court and am sympathetic with their indicated leaning toward the allowance of interest as damages. I note that in only two of our previous decisions, Leet v. Joder, 75 Wyo. 225, 244, 295 P.2d 733, 740 (1956), and In re Johnson’s Estate and Guardianship, 78 Wyo. 173, 186, 320 P.2d 429, 433, 72 A.L.R.2d 745 (1957), has this court ventured any discussion of the subject of interest as damages and both are inconclusive on the point. My own perusal of the texts and authorities cited in note 3 of the majority opinion, particularly Prejudgment Interest as Damages: New Application of an Old Theory, 15 Stanford L.Rev. 107 (1962-63) has convinced me that this court needs to reappraise carefully what is to me the unreasonably narrow and inequitable rule of our earlier decisions, and seriously consider whether this court has kept in step with the developing jurisprudence of our sister states on the allowance of interest. Our legislature’s amendment of the statute, as shown in the majority opinion, raises interesting questions. If I appear in this note to be talking against my convictions, it is for the reason that those questions should be considered only as they are presented in briefs and arguments of counsel. For this reason I limit my dissent to the narrow issue of allowance of interest as a matter of law upon a readily computable claim.