# Non-idempotent intersection types and strong normalisation

@article{Bernadet2013NonidempotentIT,
title={Non-idempotent intersection types and strong normalisation},
journal={Log. Methods Comput. Sci.},
year={2013},
volume={9}
}
• Published 6 October 2013
• Mathematics, Computer Science
• Log. Methods Comput. Sci.
We present a typing system with non-idempotent intersection types, typing a term syntax covering three different calculi: the pure {\lambda}-calculus, the calculus with explicit substitutions {\lambda}S, and the calculus with explicit substitutions, contractions and weakenings {\lambda}lxr. In each of the three calculi, a term is typable if and only if it is strongly normalising, as it is the case in (many) systems with idempotent intersections. Non-idempotency brings extra information into…

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