We consider the probabilistic applicative bisimilarity (PAB) --- a coinductive relation comparing the applicative behaviour of probabilistic untyped λ-terms according to a specific operational semantics. This notion has been studied by Dal Lago et al. with respect to the two standard parameter passing policies, call-by-value (cbv) and call-by-name (cbn), using a lazy reduction strategy not reducing within the body of a function. In particular, PAB has been proven to be fully abstract with respect to the contextual equivalence in cbv [6] but not in lazy cbn [16].
@inproceedings{paperbot5541,
title = {The Benefit of Being Non-Lazy in Probabilistic λ-calculus},
author = {Gianluca Curzi and Michele Pagani},
booktitle = {LICS},
year = {2020},
doi = {10.1145/3373718.3394806}
}