412 U.S. 441, 93 S.Ct. 2230, 37 L.Ed.2d 63 (1973); Cleveland Bd. of Ed. v. LaFleur, 414 U.S. 632, 94 S.Ct. 791, 39 L.Ed.2d 52 (1974). However, any substantive rule of law may implicitly make certain evidence irrelevant in determining the ultimate rights of parties. For example, in California, evidence brought more than two years after a child’s birth that a certain person is the biological father of the child is irrelevant for purposes of determining the paternity of a child bom into a marriage. See Cal.Fam. Code §§ 7540-7541 (West 1994). This “conclusive presumption” was upheld in Michael H. v. Gerald D., 491 U.S. 110, 109 S.Ct. 2333, 105 L.Ed.2d 91 (1989) (Scalia, J., plurality opinion). See also Mourning v. Family Publications Serv., Inc., 411 U.S. 356, 93 S.Ct. 1652, 36 L.Ed.2d 318 (<HOLDING>). It therefore follows that the mere fact that
holding that a person signing an arbitration agreement using power of attorney is not a party to that agreement merely by virtue of having signed it recognizing irrebuttable presumption as synonymous with conclusive presumption which is a presumption that cannot be overcome by any additional evidence or argument because it is accepted as irrefutable proof that establishes a fact beyond dispute holding that an arbitration agreement is separable from the underlying agreement holding rule that any payment agreement having four or more installments is a finance agreement not an improper conclusive presumption holding that where one party had received a written agreement and conformed his conduct to that agreement for an extended period of time but failed to sign the agreement he was equitably estopped from denying the validity of the agreement