T. B. D. v. Florida

concluding that threats of violence and fighting words are proscribable because government has “valid interest” in protecting citizens both from fear of violence and violence | discussed in 30B Charles Alan Wright & Michael H. Graham, Federal Practice and Procedure § 7022, at 202 n. 1 (2000) | “[T]he application of the doctrine of equivalents rests on the sub-stantiality of the differences between the claimed and accused products or processes, assessed according to an objective standard.” | “The trial judge does not have discretion to choose whether to apply the doctrine of equivalents when the record shows no literal infringement.” | experts are “supposed to testify impartially in the sphere of their expertise”