To create the executable for the untyped arithmetic expression interpreter, type make clean make to the shell. The executable will then be called "f", and you can type ./f foo to run the interpreter on file foo. See test.f for examples of the input syntax. E.g., ./f test.f will run test.f through the interpreter. f-linux is the linux version of the executable, and on the CIS linux system you can invoke it as ~stough/705/untyped/f-linux.