Irving M. Copi was a logician who studied under Bertrand Russell while at the University of Chicago. He held appointments at, among other institutions, Princeton University, the University of Michigan, and the University of Hawaii at Manoa. Among the books he published before his death in 2002 was, The Theory of Logical Types (Routledge, 1971).
Carl Cohen is the Senior Faculty Member in the Department of Philosophy at University of Michigan, having taught at this university since 1955. Among his many published books, the most recent is A Conflict of Principles: The Battle over Affirmative Action at the University of Michigan (2014).
Victor Rodych is Professor of Philosophy at the University of Lethbridge. He has published extensively on Ludwig Wittgenstein’s philosophy of mathematics. Together with Timothy Pope, Rodych is working on, Ludwig Wittgenstein, Writings on Mathematics and Logic, 1937-1944, to be published in three volumes by Cambridge UP.