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[The path: from where to where?].

The ML module system supports the modular development of large programs, through decomposition, abstraction and reuse. To increase its flexibility, much work has been devoted to extending it with recursion. To keep type normalization terminating in such an extension, thus to keep type checking decidable, path references must be resolved in a terminating way. Here paths are a mechanism to refer to components of modules. In this paper, we show that the termination of path resolution is undecidable for a ML-like module system with recursive modules and first-order applicative functors, by encoding any Turing machine. This demonstrates the need for some restriction.