HTab, a hybrid logic tableau prover
HTab is a tableau-based satisfiability checker. It currently handles the hybrid logic H(:,E,down-arrow) with role inclusions, and terminates on input within any fragments that exclude the down-arrow operator.
Relevant references for HTab are  and  for the general tableau algorithm and  for the pattern-based blocking and lazy branching technique currently used.
Download the source code of HTab either using Darcs:
darcs clone --lazy http://hub.darcs.net/gh/htab
Or downloading the source code as a zip file and unpacking it.
Compiling and using
A help is available by running:
Example of use with Relation-Changing formulas
--translate flag interprets input formulas as Relation-Changing ones, and translates them to Hybrid Logic. There is no guarantee that HTab will terminate on such formulas since they are translated to HL(:,E,down-arrow).
Example formulas are provided in the
The following command runs the translation and hybrid tableau algorithm on the input formula
swap_no_tree introduced in  :
htab --translate -f rc/swap_no_tree.frm
Since the translation preserve equivalence, it is interesting to have a look at the model created from an open branch.
-m mod flag writes a model into the
mod file (if the formula is satisfiable). It does so in a specific format undestandable by HTab and Hylolib. Using the
-d flag, one can ask Htab to generate the model into the dot graphviz format:
htab --translate -f rc/swap_no_tree.frm -d -m mod dot mod -Tpdf -O evince mod.pdf
If some relation-changing formula makes HTab run forever, you may want to use the flag
--sembranch=no to disable the semantic branching technique, which can be problematic in the presence of many nominals and binders:
htab --translate -f rc/swap_diamond.frm --sembranch=no -d -m mod
 https://cs.famaf.unc.edu.ar/~hoffmann/publi/2009_m4m_htab.pdf  https://cs.famaf.unc.edu.ar/~hoffmann/publi/2010_jal.pdf  http://www.ps.uni-saarland.de/papers/abstracts/GoetzmannKaminskiSmolkaSpartacus.pdf  https://cs.famaf.unc.edu.ar/~hoffmann/publi/2013_swap_igpl.pdf