Well... would this satisfy you? (I removed the _add part for convenience. You could still argue that `_concat` is not a literal... if by literal you mean a prim

Well... would this satisfy you? (I removed the _add part for convenience. You could still argue that `_concat` is not a literal... if by literal you mean a primitive provided by the language itself. Note that i'm not claiming that this is a dependent type system. But you can emulate some features of such a type system.) https://www.typescriptlang.org/play?#code/C4TwDgpgBAggTnAPAOyhAHsCyAmBnKZAVwFsAjCOAGigH1a4IBjNTbfKAQ2RAG0BdALwCAfFEEAoKNMKkKcVllwFkUmeoD8XHgLXrpALj10GzXgCIANtgDmwABbn+i9iuOaTjJu5kHYCFBpeADpQ+i8abhB+EQk40Eg6JgB7ZCZOYEQYF2VtPn4aACEcjijRcWNickoSghgLa2Q7R34faS0y1v1fSrkajCUOQobbByc2qA6dLu6oI3VigdcoXgBLZAAzGsKABhpQ4PWthQAlGe6tWhS0jMQQ0JginYKoE9jZueMYOI2iNOBVqkoNd0pkYI1arJqtQoIUIUtclV5CIABTGTiNPzg7BUYxkTGwxq49ScLEBbHIETEmRkMlIOHYKkSACUfiuqVBWXJjSp-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-KMt5HykrAeAMeotKwhlEyskk8nhbFYiCO8HwyOaUqyvKirKuVMhajqUAHPqulCcCgbumRhnWd6e4JkhXFQDxe7+oJVZOugTCdQ2nUoruA5KXei37n6i2Hgm7VTZ1daza682Botn7wSt-rrTQ5g5rQpY8LQU4QCQeBOMyQA https://www.typescriptlang.org/play?#code/C4TwDgpgBAggTnAPAO...