Patents of processes are actually explicitly allowed: 35 U.S.C. 101: "Whoever invents or discovers any new and useful _process_, machine, manufacture, or compo

Patents of processes are actually explicitly allowed: 35 U.S.C. 101: "Whoever invents or discovers any new and useful _process_, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title." https://www.law.cornell.edu/uscode/text/35/101 https://www.law.cornell.edu/uscode/text/35/101