The figure title appearing in the legend includes the following sentence,
Figure 1: Schematic illustrating the non- one-to-one relationship between hypotheses, process models, and statistical models.
The only thesaurus with an entry for 'one-to-one' that I have found is WordNet. They provide only "matched" as a 'similar to' entry (not quite a synonym). The word I'm looking for should refer to matching relationships that are not one-to-one. I would also accept any answer that contains any true synonyms that could lead to an antonym. Or, is simply "non-one-to-one" the way to go? It's not the most aesthetically pleasing option.