OPINION
JONES, Chief Justice.The executors of this estate petitioned the Orphans’ Court Division to reduce the appraisement of certain assets made by the Commonwealth for purposes of imposing its transfer inheritance tax. The auditing judge sustained the taxpayers’ position at a hearing held at the audit of the executors’ account. 24 Fiduc.Rep. 352 (C.P. Allegheny, 1974). Exceptions having been dismissed by the court en banc, the Commonwealth appealed.1
The case was tried on an agreed stipulation of facts which can be fairly summarized as follows.
*58John Evans Rose died on March 15, 1972. On or about May 18, 1973, his two sons, as executors, filed the Pennsylvania inheritance tax return for the estate. On November 14, 1973, the Pennsylvania Department of Revenue submitted to the executors, appellees herein, its Notice of Filing Appraisement. The appraiser for the Commonwealth increased the valuation of two items which were included on the inheritance tax return, and included a third item which the executors had omitted. The first item reappraised was the decedent’s undistributed share of partnership profits from his law firm. The Commonwealth’s appraisement was $35,501.54. Appellees assert that the true value of the asset for Pennsylvania inheritance tax purposes is $22,799.00. The difference in valuation accurately reflects the amount of federal and state income tax which was properly paid on this item by the Estate since the item was “income in respect of a decedent,” which had accrued to the decedent, but on which no income tax had been paid by the decedent because the decedent was a cash basis taxpayer.
The second item reappraised was the decedent’s right to receive proceeds from the sale of 200 shares of common stock of Joy Manufacturing Company from the brokerage house of Parker/Hunter, Inc., which proceeds were also stipulated as “income in respect of a decedent.” The executors valued this item at $12,734.85 and the Commonwealth appraised the item át $14,083.86. Again, the differential was the amount of federal and state income tax which the executors paid on the item.
The third item under contention is the amount of $1,635.68 representing post-mortem dividends, accumulated dividends, and returns of unearned premiums arising from several insurance policies on decedent’s life which benefits were not listed by the executors as assets of the decedent’s taxable estate. The Commonwealth asserts that these items are taxable assets. Appellees insist that these assets are not taxable for Pennsylvania in*59heritance tax purposes because they are proceeds of insurance on the life of decedent which were payable directly to beneficiaries other than decedent’s estate, and as such, they are specifically exempted from inheritance tax by the Inheritance and Estate Tax Act of 1961, June 15, P.L. 373, article III, § 303, 72 P.S. § 2485-303.
We affirm that portion of the lower court’s decree which allowed a devaluation to reflect income taxes paid but remand that portion of the decree which determined that the additional insurance benefits were “proceeds of insurance.”
I
The auditing judge ruled that the value of decedent’s accrued income items (the undistributed share of partnership profits and the right to proceeds from the sale of stock) should reflect the deferred payment of federal and Pennsylvania income taxes payable in these accrued income items. The opinion and the order below relied on the decision in Tench Estate, 23 Fiduc.Rep. 478 (C.P.Allegheny, 1973) 2 which was never appealed by the Commonwealth. In Tench, the decedent owned a one-third interest in a partnership through which the payments on accounts receivable flowed. As in the present case, this accrued item represented “income in respect of a decedent” for federal income tax purposes. Int.Rev. Code of 1954, § 691.3 On such items of income, the es*60tate or beneficiary is liable to pay federal income tax. The Tench court reasoned that the asset contained in built-in encumbrance so that if the Pennsylvania inheritance tax value were the full present worth of the receivable, the result would be the imposition of Pennsylvania inheritance tax upon federal income taxes. The only substantial difference between Tench and the present case is that appellees here received a devaluation for the amount of Pennsylvania income taxes paid as well as for federal income taxes.
The Commonwealth’s alleged statutory basis for the taxation of the full value of the two items of “income in respect of a decedent” begins with Section 401 of the Inheritance and Estate Tax Act of 1961, 72 P.S. § 2485-401. Under the heading of “Method of computation of tax; residents,” this section states that “. . . the tax shall be computed upon the value of the property, in excess of the deductions hereinafter specified, at the rates in effect at the transferor’s death.” Appellees readily concede that deductions for income taxes imposed after the decedent’s death are not provided for in the Act and that deductions not specifically enumerated are not allowable. Inheritance and Estate Tax Act, §§ 601, 621, 72 P.S. §§ 2485-601,-621; Lazar Estate, 437 Pa. 171, 260 A.2d 734 (1970). Since no deduction is allowable, the Commonwealth argues that the word “value” in Section 401 is necessarily the gross value of the assets reduced to present worth with no allowance in the valuation for the federal and state income taxes paid.4
*61The gist of appellees’ argument is that because of a technical change in federal tax law in 1942, unaccompanied by any substantial change in Pennsylvania inheritance tax law, the taxation by the Commonwealth of that portion of the decedent’s estate which represents federal and state income tax is a windfall to the Commonwealth and unfair.
As the auditing judge (McKenna, P. J.) pointed out in his opinion, prior to 1942, the death of a taxpayer owning an accrued income asset caused an immediate acceleration of the federal income tax obligation attached to that asset. The accrued income was reported on the decedent’s final federal income tax return, Helvering v. Es*62tate of Enright, 312 U.S. 636, 61 S.Ct. 777, 85 L.Ed. 1093 (1941), and the income tax attributable thereto was deductible as a debt of the decedent for Pennsylvania Inheritance Tax purposes. Cf. Payne Estate, 48 Pa.D. & C. 578 (O.C.Erie, 1943).
After 1942, however, the Internal Revenue Code shifted this income tax burden to the decedent’s estate or to the beneficiaries. Hence, the income tax obligation was no longer technically a debt of the decedent, thus enabling the Department of Revenue to successfully assert for many years that the income tax was non-deductible. The Pennsylvania Personal Income Tax Act of 1971 similarly imposes the burden of paying the tax upon the estate or beneficiary, 1971, March 4, P.L. 6, No. 2, § 305, added 1971, August 31, P.L. 368, No. 93, § 4, 72 P.S. § 7305 (Cum.Supp., 1975-76).
Faced with the non-deductibility of federal and state income tax from Pennsylvania inheritance tax obligations, the executors successfully persuaded the lower court that, for purposes of valuation, the federal and state income taxes paid may not be included in the present worth of the accrued income items. According to appellees, the unfairness in the Commonwealth’s attempted valuation scheme lies in the facts that the Commonwealth’s valuation does not reflect the real economic position of the beneficiaries and that Pennsylvania inheritance tax will be paid upon Pennsylvania income tax and upon federal income tax. This amounts to two counts of double taxation.
The federal and state governments may generally tax the same subject matter at the same time and neither the United States nor the state, in determining the amount of tax due to it, is under constitutional obligation to make any allowance on account of the tax of the other. Frick v. Pennsylvania, 268 U.S. 473, 499, 500, 45 S.Ct. 603, 69 L.Ed. 1058 (1925), affirming in part, Frick Estate, 277 Pa. 242, 121 A. 35 (1923).
*63Similarly, there is no constitutional prohibition which prevents the state from taxing the same subject matter twice, Puntureri v. Pittsburgh School District, 359 Pa. 596, 60 A.2d 42 (1948), so long as the taxes are of a different kind, Commonwealth v. Harrisburg Light & Power Co., 284 Pa. 175, 130 A. 412 (1925), and do not violate the requirement of uniformity contained in Article VIII, Section 1 of the Pennsylvania Constitution. Dunkard Township School Tax Case, 359 Pa. 605, 60 A. 2d 39 (1948); Plumy v. Philadelphia School District, 182 Pa.Super. 122, 126 A.2d 768 (1956).
However, because of the harshness which results from double taxation, the courts of this Commonwealth have developed certain rules of construction to insure that double taxation is not imposed arbitrarily. Thus, if the intent of the Legislature is unclear in imposing double taxation, there is a presumption against such a legislative purpose, which can only be overcome by express statutory language. Dixon’s Case, 138 Pa.Super. 385, 11 A.2d 169 (1940); Arrott’s Estate, 322 Pa. 367, 185 A. 697 (1936) ; Commonwealth v. Harrisburg Light & Power Co., supra. Statutes and ordinances will be construed to avoid double taxation if such construction is possible. Puntureri v. Pittsburgh School District, supra; Paul’s Estate, 303 Pa. 330, 154 A. 503, cert. denied, 284 U.S. 630, 52 S.Ct. 13, 76 L.Ed. 536 (1931); Plumy v. Philadelphia School District, supra. These rules would appear to be corollaries of the more basic principle that a statute imposing a tax must be strictly construed,5 and all reasonable doubt must be resolved in favor of the taxpayer. Pickering Estate, 410 Pa. 638, 190 A.2d 132 (1963); Loeb Estate, 400 Pa. 368, 162 A.2d 207 (1960).
Our issue thus narrows itself to whether the Legislature clearly expressed an intent that no allowance be granted in the inheritance tax valuation for the pay*64ment of income taxes. Clearly, there is no express statutory authorization, and reasonable doubt exists as to the intent of the Legislature to impose double taxation in this instance. The disallowance of the income taxes as a deduction, accomplished not by a substantive change in Pennsylvania inheritance tax law, but rather by changes made by the United States Congress in the income tax provisions of the Internal Revenue Code and by the imposition of the Pennsylvania personal income tax, cannot be construed as an affirmative intent on the part of the Pennsylvania legislature to impose double taxation in two respects by disallowing a devaluation of the assets to reflect the amount of income taxes paid. To hold otherwise would be to enforce double taxation by implication and speculation, which is contrary to the legal principles enunciated in our caselaw.
Even aside from the considerations of statutory construction, plain logic defeats the position of the Commonwealth. It argues that since no inheritance tax deduction is allowed for these income taxes, it is necessarily inferable that the Legislature did not intend to allow the income taxes to decrease valuation of the items. Nowhere does the Act provide for the discount of an item of accrued income by the amount of federal and state income taxes paid. The logical conclusion of such an argument is that unless an item is deductible, it is not an available consideration for purposes of valuation. Such a conclusion would lead to an absurd result since it would preclude consideration of factors which are not specifically deductible, but which have always been relevant to valuation. Unless the Legislature specifically precludes income taxes as a factor in determining the present worth of an item, we are not willing to intrude upon a completely logical calculation.6
The Commonwealth asserts in its brief that the construction which we today impose upon the Inher*65itance and Estate Tax Act is a violation of the uniformity clause of the Pennsylvania Constitution, Article VIII, Section 1. It relies upon Amidon v. Kane, 444 Pa. 38, 279 A.2d 53 (1971) for the proposition that the reflection of accrued income taxes in the valuation of income in respect of a decedent will not be uniform because the graduated federal income tax rates attributable to an asset will differ from taxpayer to taxpayer. Although we recognize the importance of this issue, it is, unfortunately, not reviewable by us because of appellant’s failure to file an exception in regard to this issue. Sup.Ct.O.C. Rules, § 3, rule 1, and Pa.R.C.P. 1518. Commonwealth v. Tolleson, 462 Pa. 193, 340 A.2d 428 (1975); Turnway Corporation v. Soffer, 461 Pa. 447, 336 A.2d 871 (1975); Banes Estate, 461 Pa. 203, 336 A.2d 248 (1975). Although exceptions were filed by the Commonwealth, none of the exceptions were even remotely related to the constitutional issue of uniformity. Even though it is probable that the issue was argued orally to the court en banc, the short opinion of that tribunal gives no hint as to whether the issue was considered by it, and at any rate, Rule 1518 requires that an exception be filed (i. e. written) and that it deal with each separate objection “precisely.” “Matters not covered by exceptions are deemed waived, unless, prior to final decree, leave is granted to file exceptions raising these matters.” Pa.R.C.P. 1518. Even constitutional issues may be waived. Altman v. Ryan, 435 Pa. 401, 257 A.2d 583 (1969). The burden was on appellant to preserve this issue for appellate review.
II
Regarding the various dividends and unearned premiums paid to named beneficiaries under the terms of insurance policies on the life of the decedent, we are not convinced by the analysis of the lower court that these *66items of income are proceeds of insurance on the life of the decedent.
Section 303 of the Inheritance and Estate Tax Act (72 P.S., § 2485-303) states:
“All proceeds of insurance on the life of the decedent, unless payable to the estate of the decedent, are exempt from inheritance tax. Proceeds payable to an inter vivos or testamentary trustee or other beneficiary designated in the decedent’s will or in an inter vivos instrument of transfer are exempt from inheritance tax within the meaning of this section.”
The nine policies involved here were payable to named beneficiaries or to an insurance trust. The additional benefits other than the face values of the policies which accrued to the beneficiaries amount to $1,635.68. The original stipulation between the parties did not elaborate upon the nature of these additional benefits and the opinion of the lower court chose to treat them collectively. The auditing judge reasoned that because the various benefits were “fused” into the policies of insurance and were payable to the beneficiaries as “fruits of the policies,” such benefits were proceeds of insurance and thus, exempt from taxation.
We find this analysis to have been somewhat cavalier. A supplemental stipulation between counsel, filed of record some three and one-half months before the opinion was handed down, elaborated upon the initial stipulation by dividing the additional insurance benefits into more specific categories: post-mortem dividends; accumulated dividends; and return of unearned premiums. The stipulation further requested that the auditing judge take judicial notice of the nature of these insurance payments but reserved the right to the parties to present evidence on these matters. The auditing judge failed to consider this additional stipulation in his opinion.
Both parties in their briefs to this Court have quoted extensively from insurance textbooks to enlighten us as *67to the nature of these benefits. We feel that an analysis of the benefits should more properly be conducted in the court below so that evidence may be heard, where necessary to enlighten the court as to the nature of these proceeds. Furthermore, the analysis by the court below that these benefits are fused into the policies and are fruits of the policies is not, in any event, the correct analysis.
Federal caselaw which deals with “the amount receivable ... as insurance under policies on the life of the decedent” (Int.Rev.Code of 1954, § 2042) is most helpful in determining what is meant by “proceeds of insurance” in the Pennsylvania statute. It is manifestly clear that even though a contract may be labeled one of “insurance,” such designation does not by itself entitle the estate to the tax breaks given to insurance either under Federal or State law. For instance, annuity payments, even if joined together in the same contract with insurance payments, are not entitled to treatment as insurance. Estate of Keller v. Commissioner, 312 U.S. 543, 61 S.Ct. 651, 85 L.Ed. 1032 (1941); Helvering v. Le Gierse, 312 U.S. 531, 61 S.Ct. 646, 85 L. Ed. 996 (1941); Bayer’s Estate, 345 Pa. 308, 26 A.2d 202 (1942); Wright Estate, 11 Fiduc.Rep. 503 (1961). The controlling criterion is whether the payments arose out of the exposure of the insurer to an insurance risk. Estate of Keller v. Commissioner, supra; Chew’s Estate v. Commissioner, 148 F.2d 76 (5th Cir.), cert. den., 325 U.S. 882, 65 S.Ct. 1575, 89 L.Ed. 1997 (1945); Seward’s Estate v. Commissioner, 164 F.2d 434 (4th Cir. 1947). In other words, the proceeds must arise by way of a transaction possessing features of insurance risk-shifting and risk-distributing, i. e., from the risk of loss of life of the insured. If the payment of the additional premiums and dividends are contingent upon criteria which are severable under the terms of the contract from the insurance *68risk, such payments are not encompassed within the proceeds of insurance exemption.
Accordingly, the portion of the decree which allowed a reduction in valuation for the amount of income tax payments on the items of income in respect to a decedent is affirmed. That portion of the decree which allowed an exemption for additional benefits arising from insurance contracts is vacated and remanded for reconsideration in accordance with the principles enunciated above. Each party to pay own costs.
ROBERTS, J., filed a concurring opinion. MANDERINO, J., concurred in the result. NIX, J., filed a concurring and dissenting opinion. POMEROY, J., filed a dissenting opinion in which EAGEN, J., joins.. Jurisdiction is in this Court by virtue of Act of 1970, July 31, P.L. 673, article II, § 202(3), 17 P.S. § 211.202(3) (Cum.Supp. 1975-6).
. This case has been criticized in Fiduciary Review, September, 1973.
. Neither in section 691 nor elsewhere in the Internal Revenue Code is the term “income in respect of a decedent” defined. Generally, however, the term may be defined as a right to income that the decedent owned at his death but which, under his method of accounting, was not includable in his final income tax return. Typically, it includes any accrued income to date of death for a cash basis decedent/taxpayer. Richman, Income in Respect of a Decedent Can Take Many Forms: Some Planning is Possible, 28 J.Tax 202 (1968).
“Income in respect of a decedent” is included in the decedent’s estate tax return and the income tax return of the estate or bene*60ficiary. Int.Rev.Code, § 691(c) provides a Federal income tax deduction for federal estate taxes applicable to the inclusion in the gross estate of “income in respect of a decedent.” Without this specific statutory income tax deduction, such items would be subjected to double taxation by the federal government.
. The Commonwealth contends that the allowance of a devaluation to reflect income taxes will seriously encroach upon the statutory definition of “value” which is contained in the Inheritance and Estate Tax Act at Section 102(24), 72 P.S. § 2485-102(24):
“ ‘Value’ means the price at which the property would be sold by a willing seller, not compelled to sell, to a willing buy*61er, not compelled to buy, both of whom have reasonable knowledge of the relevant facts.”
This definition, suggested by Federal Estate Tax Regulation, § 20.-2031-l(b), is summarized as “fair market value.” Although the Commonwealth stipulated to the fact that the valuation differential of the two items of income in respect of a decedent accurately reflects the amount of federal and state income tax paid on the items, it argues that the definition of value necessarily means gross value with no credit allowed for income taxes paid. This is so, it argues, because if the executors put the two assets on the auction block, no willing buyer would feel obliged to discount his offer by the amount of income tax due because the buyer would take the items free of any claims for income taxes, since absent a lien, the buyer would not be obligated to pay the income taxes.
We believe that the concept of value, as stated in Section 102 (24) means “net value” which reflects any built-in encumbrance or inherent charge on the particular assets other than the inheritance and estate tax itself. In this situation, where any sale contemplated by the fair market value test is entirely theoretical, and neither side presented evidence as to the effect of the income tax charges on market forces, it was proper for the auditing judge to assess the items to reflect the real value of the asset to the particular decedent’s estate. Cf. Banker’s Trust Company v. United States, 284 F.2d 537 (2d Cir. 1960). Under federal caselaw, the determination of fair market value has always been a factual issue. Helvering v. Maytag, 125 F.2d 55 (8th Cir. 1942). Thf only legal issue is whether the income taxes are legally cognizable criteria to be employed in the assessment of value. Powers v. Commissioner, 312 U.S. 259, 61 S.Ct. 509, 85 L.Ed. 817 (1941). We are not convinced that the Inheritance and Estate Tax Act’s definition of value precludes the consideration of income tax charges in the valuation scheme, since there is no relevant direction contained in the statute and there was no evidence of market forces presented to the auditing judge.
. 1 Pa.C.S. § 1928(b)(3) (Cum.Supp.1975-6).
. See footnote three, supra.