## Weak theories of concatenation and arithmetic.(English)Zbl 1251.03075

Summary: We define a new theory of concatenation WTC which is much weaker than Grzegorczyk’s well-known theory TC. We prove that WTC is mutually interpretable with the weak theory of arithmetic R. The latter is, in a technical sense, much weaker than Robinson’s arithmetic Q, but still essentially undecidable. Hence, as a corollary, WTC is also essentially undecidable.

### MSC:

 03F25 Relative consistency and interpretations 03F30 First-order arithmetic and fragments 03B25 Decidability of theories and sets of sentences
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### References:

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