I would have said, "that LOOKS contradictory but isnt"
because one is index and the other is a level but notationally they refer to the same syntactic construct, and therefore an assertion of value differs by intent. Index 1, level 0, Same syntax to represent.
To me, it "looks" contradictory. It has to be explained by word not by statement in notation.
If you combine these two naming schemes in the same syntax, of course it will be ambiguous. In the examples of the K combinator, they don't clash with each other though, as those are different examples.
because one is index and the other is a level but notationally they refer to the same syntactic construct, and therefore an assertion of value differs by intent. Index 1, level 0, Same syntax to represent.
To me, it "looks" contradictory. It has to be explained by word not by statement in notation.