I've noticed that the 'in' function appears to accept any pair of arguments; it returns 'false' in the case that the arguments make no sense. I suppose that some file has defined in(x::Any,y::Any) to be false. Why is this so? This definition appears to impede debugging because, for example, if a programmer accidentally reverses the two arguments to 'in()' or makes some less obvious blunder with types, no error message is issued.
Thanks, Steve Vavasis
