In re Estate of Shields, 84 Ariz. 330, 331, 327 P.2d 1009, 1010 (1958). If the language of the will is reasonably susceptible to two interpretations, we may consider extrinsic evidence to ascertain the testator’s intent. Smith, 119 Ariz. at 295-96, 580 P.2d at 756-57. Extrinsic evidence is not, however, admissible to contradict the plain language of the will. Hill v. Hill, 37 Ariz. 406, 410, 294 P. 831, 833 (1931). If extrinsic evidence is admissible, interpreting the will generally becomes a question of fact. In re Estate of Black, 211 Cal.App.2d 75, 27 Cal.Rptr. 418, 427 (1962). See Taylor, 175 Ariz. at 159, 854 P.2d at 1145; United California Bank v. Prudential Ins. Co. of America, 140 Ariz. 238, 260, 681 P.2d 390, 412 (App.1983) (“[A]ny ambiguity in ... documents is subject to a factual determination concerning ... intent ... and is to be resolved conclusively by the trier of fact.”).
IMPLEMENTATION OF THE TRANSITIONAL RULE
¶ 11 Kreigh and the IRS interpret time-of-death marital deduction provisions as preventing application of the transitional rule as a matter of law. See also Liberty Nat’l Bank, 867 F.2d at 305. Although we agree with the underlying rationale of these authorities, allowing these provisions to control the distribution of the estate as a matter of law could, in some cases, conflict with the primary goal in construing wills: ascertaining the testator’s intent. See Krokowsky, 182 Ariz. at 280, 896 P.2d at 250. If the will is reasonably susceptible to two interpretations, that goal is better served by determining the testator’s intent as a question of fact. See In re Estate of Black, 27 Cal.Rptr. at 427; Taylor, 175 Ariz. at 159, 854 P.2d at 1145; United California Bank, 140 Ariz. at 260, 681 P.2d at 412.
¶ 12 Questions of fact, however, may be subject to presumptions which shift the burden of going forward with evidence. In re Hesse’s Estate, 62 Ariz. 273, 282, 157 P.2d 347, 351 (1945). A presumption that a testator who includes a time-of-death marital deduction provision in his will intends the current unlimited marital deduction to apply would keep our application of the transitional rule fundamentally consistent with the federal authority on that federal rule and would properly focus on the will’s language as the most reliable expression of the testator’s intent. See In re Estate of Johnson, 168 Ariz. 108, 110, 811 P.2d 360, 362 (App.1991). It does not, however, prevent the court from finding a different intent based upon competent evidence. We, therefore, adopt the presumption and, in the presence of a time-of-death marital deduction provision, we will apply the unlimited marital deduction absent evidence rebutting the presumption.
BENJAMIN’S INTENT
¶ 13 Benjamin’s will became reasonably susceptible to two interpretations upon passage of the ERTA with the transitional rule.
See Arend, 373 N.W.2d at 342. The trial court thus properly admitted extrinsic evidence to resolve this question of fact.
See Smith, 119 Ariz. at 295-96, 580 P.2d at 756-57;
Taylor, 175 Ariz. at 154, 854 P.2d at 1140.
See also Arend, 373 N.W.2d at 342. In reviewing a trial court’s findings of fact, we do not reweigh conflicting evidence or redetermine the preponderance of the evidence, but examine the record only
to determine whether substantial evidence exists to support the trial court’s action.
Whittemore v. Amator, 148 Ariz. 173, 175, 713 P.2d 1231, 1233 (1986). Substantial evidence is evidence which would permit a reasonable person to reach the trial court’s result.
Hutcherson v. City of Phoenix, 192 Ariz. 51, ¶ 13, 961 P.2d 449, ¶ 13 (1998).
¶ 14 The trial court relied on the provisions in the Third paragraph of Benjamin’s will, which emphasized that Benjamin’s primary intent was to maximize the marital deduction and specifically required that the marital deduction in effect at the time of his death apply to his estate. Although the initial presumption we have established in favor of the unlimited marital deduction applies here because of the time-of-death marital deduction directive in Benjamin’s will, the trial court received evidence concerning Benjamin’s disinherited heirs and concerning the notes and standard drafting practices of the attorney who drafted the will. This evidence