Finding of infringement under 35 U.S.C. § 271(a) requires that each step of claimed process be performed in United States. In the present case, process claims for operation of wireless e-mail transmission system are not, as matter of law, infringed by accused system, since each of asserted claims recites step that utilizes “interface” or “interface switch,” and this step is satisfied in accused system only by “relay” that is located in Canada.