concurring.
According to the Supreme Court, claim construction is a matter for the judge, and not the jury. Markman v. Westview Instruments, Inc., — U.S. -, -, 116 S.Ct. 1384, 1395, 134 L.Ed.2d 577 (1996). As such, if the claim construction does not require the resolution of disputed material facts, it may be treated as a matter of law and so reviewed by this court. However, where material facts are disputed, claim construction requires resolution of both questions of fact and questions of law, Markman, — U.S. at -, 116 S.Ct. at 1390 (classifying claim construction as a “mongrel practice”), and this court may be required to give due deference to the trial court’s factual findings. Metaullics Sys. Co. v. Cooper, 100 F.3d 938, 939, 40 USPQ2d 1798, 1799 (Fed.Cir.1996); see Fed.R.Civ.P. 52(a). In this case, there was remarkable agreement among those skilled in the art — including the inventor and both parties’ technical experts — about the equivalence of off-hook and inter-digit time-out methods under 35 U.S.C. § 112(6) (1994) and the last-digit determination methods described in the specification. Thus, there was no call for the district court to make findings of fact about the meaning of disputed limitations en route to its construction of the claims. Accordingly, I agree with the resolution of this case.