@INPROCEEDINGS{AntoyHanus17PADL,
author    = "Antoy, S. and Hanus, M.",
title     = "Eliminating Irrelevant Non-determinism in Functional Logic Programs",
year      = "2017",
pages     = "1-18",
booktitle = "Proc. of the 19th International Symposium on
     Practical Aspects of Declarative Languages (PADL 2017)",
publisher    = {Springer LNCS 10137},
abstract = {
Functional logic programming languages support non-deterministic search
and a flexible use of defined operations by applying them
to unknown values.
The use of these features has the risk that equal values
might be computed several times or I/O computations
could fail due to non-deterministic subcomputations.
To detect such problems at compile time,
we present a method to locate non-deterministic operations.
If the non-determinism caused by some operation
is semantically not relevant,
the programmer can direct the compiler to produce only one result of
a computation.  If all the results of the computations are equal,
this directive preserves the semantics and improves
the operational behavior of programs.
We define the declarative meaning of such annotations
and propose both testing and verification techniques that respectively
increase the confidence or formally prove that the non-determinism of
an operation is irrelevant.
}
}