code: def nein(x):
      "this is 'not' but not is a keyword so it's 'nein'"
      if not isinstance(x,(bool,ThreeVL)): raise TypeError(type(x))
      return not x if isinstance(x,bool) else ThreeVL(dict(t='f',f='t',u='u')[x.value]f nein(x):
      "this is 'not' but not is a keyword so it's 'nein'"
      if not isinstance(x,(bool,ThreeVL)): raise TypeError(type(x))
      return not x if isinstance(x,bool) else ThreeVL(dict(t='f',f='t',u='u')[x.value])
docs: this is 'not' but not is a keyword so it's 'nein