(“A statute is presumed to have been enacted by the legislature with complete knowledge of the existing law and with reference to it.”). Section 171.106(a) expressly states that the single-factor formula applies “[e]xcept as provided by this section.” See Tex. Tax Code § 171.106(a). Chapter 141’s three-factor formula is not listed 'among the alternative formulas in section 171.106. See id. § 171.106 (listing alternative formulas for apportioning margin to Texas). Had the legislature intended for chapter 141’s three-factor formula to be án alternative for apportioning margin for franchise tax purposes, it could have included it as one of the expressed alternatives in section 171.106. See TGS-NOPEC, 340 S.W.3d at 439; Riverside Nat’l Bank v. Lewis, 603 S.W.2d 169, 175 (Tex.1980) (<HOLDING>). Similarly, section 171.1014 addresses
holding that a broad statutory definition of a term that was inconsistent with the terms plain meaning did not affect the terms definition in other contexts holding that where only one interpretation of contractual terms is possible a court may decide the meaning of those terms as a matter of law holding because legislature knew how to include terms within statutory definition and did not do so statutory definition did not include terms in light of the terms contemporaneous inclusion of the same terms in a separate provision recognizing that in the absence of a statutory definition statutory terms are construed in accordance with their ordinary or natural meaning holding that the repeated sending of a writing which contains certain standard terms without any action with respect to the issues addressed by those terms cannot constitute a course of dealing which would incorporate a term of the writing otherwise excluded under  2207 because the repeated exchange of forms by the parties only tells buyer that seller desires certain terms given sellers failure to obtain buyers express assent to these terms before it will ship the program buyer can reasonably believe that while seller desires certain terms it has agreed to do business on other terms those terms expressly agreed upon by the parties