# Getting There and Back Again

@article{Danvy2022GettingTA, title={Getting There and Back Again}, author={Olivier Danvy}, journal={Fundam. Informaticae}, year={2022}, volume={185}, pages={115-183} }

“There and Back Again” (TABA) is a programming pattern where the recursive calls traverse one data structure and the subsequent returns traverse another. This article presents new TABA examples, refines existing ones, and formalizes both their control flow and their data flow using the Coq Proof Assistant. Each formalization mechanizes a pen-and-paper proof, thus making it easier to “get” TABA. In addition, this article identifies and illustrates a tail-recursive variant of TABA, There and…

## 2 Citations

### The Tortoise and the Hare Algorithm for Finite Lists, Compositionally

- Computer ScienceACM Transactions on Programming Languages and Systems
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This article presents a compositional account of the tortoise-and-hare algorithm for finite lists, which means that programs that use a fast and a slow pointer can be expressed with an ordinary fold function for lists and reasoned about using ordinary structural induction on the given list.

### Fold–unfold lemmas for reasoning about recursive programs using the Coq proof assistant

- Computer ScienceJournal of Functional Programming
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Fold–unfold lemmas complement the rewrite tactic in the Coq Proof Assistant to reason about recursive functions, be they defined locally or globally, and prove effective in the classroom, considering the clarity of discourse in the subsequent term reports and oral exams.

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