GPT-4: "The forward mapping M that I created to map positive integers to English sentences is based on a general guideline, where smaller-valued numbers generally correspond to shorter sentences using more common words. However, this mapping is not a perfect bijection, meaning there isn't necessarily a one-to-one correspondence between integers and sentences.
The generation of sentences is influenced by the patterns in the data I was trained on, and there is some degree of creativity involved in generating the sentences. This makes it difficult to establish a precise, invertible mapping. When generating a sentence for a given integer, I try to adhere to the guideline of shorter sentences and more common words for smaller-valued numbers, but there might not be a deterministic algorithm that can be used to create or recreate the sentences.
Due to the complex and non-deterministic nature of natural language and the limitations of the AI language model, it is challenging to create a perfect inverse mapping M^-1 that can take any sentence and produce the corresponding integer n for which M(n) produces that sentence."