style="font-variant:small-caps;">Quick[PUP]{}</span>]{}-based heuristics to the default one was implemented using [<span style="font-variant:small-caps;">\#Fallback($0,\emptyset,\emptyset,\emptyset$)</span>]{} response.

#### Setup.

The evaluation was done by using the set of instances provided by Siemens[^1]. This package comprises instances of four types: (1) double, (2) double-variant, (3) triple and (4) grid. The first three types are instances representing topologies occurring frequently in practice, whereas grids are parts of real railway systems (see [@DBLP:conf/cpaior/AschingerDFGJRT11] for details). The instances were tested with two encodings: [PUP]{}-E1 – the original straightforward encoding published in [@DBLP:conf/cpaior/AschingerDFGJRT11] (Section 3.1, p. 6) and [PUP]{}-E2 – a complex encoding comprising symmetry breaking and ordering rules used in the ASP Competition 2015. Moreover, in all experiments with [<span style="font-variant:small-caps;">wasp</span>]{}using heuristics, we removed rule 9 (line 14) from [PUP]{}-E2. This rule is a symmetry breaker that does not allow our heuristics to select the starting zone. For each encoding we grounded all instances with [<span style="font-variant:small-caps;">gringo</span>]{}(version 4.5.3). Then each solver was run for 900 sec.  on a system equipped with i7-3030K CPU, 64GB RAM and Ubuntu 11.10.

#### Results.

A summary of our evaluation results is presented in Figures \[fig:eval:a\] and \[fig:eval:b\]. The results of [<span style="font-variant:small-caps;">clasp</span>]{} [@DBLP:conf/aaai/GebserKROSW13], which was used as a reference system, show that it 