Publications in Scientific Journals:
D. Gardy, O. Bodini, B. Gittenberger, Z. Golebiewski:
"On the Number of Unary-Binary Tree-like Structures with Restrictions on the Unary Height.";
Annals Of Combinatorics,
22
(2018),
1;
45
- 91.
English abstract:
We investigate various classes of Motzkin trees as well as lambda-terms for which we derive asymptotic enumeration results. These classes are defined through various restrictions concerning the unary nodes or abstractions, respectively: we either bound their number or the allowed levels of nesting. The enumeration is done by means of a generating function approach and singularity analysis. The generating functions are composed of nested square roots and exhibit unexpected phenomena in some of the cases. Furthermore, we present some observations obtained from generating such terms randomly and explain why usually powerful tools for random generation, such as Boltzmann samplers, face serious difficulties in generating lambda-terms.
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1007/s00026-018-0371-7
Created from the Publication Database of the Vienna University of Technology.