Developed by David Purser and Joris Nieuwveld.

The code is made available under the GNU Affero General Public License.

Paper on which the Leapfrogging algorithm is based. Yuri Bilu, Florian Luca, Joris Nieuwveld, Joël Ouaknine, David Purser, and James Worrell. "Skolem meets Schanuel." MFCS 2022. doi:10.4230/LIPIcs.MFCS.2022.20, arxiv:2204.13417.

Data used in the paper: dataset

Generated using generator.py.

This guide is aimed at using the tool, for developing and deploying the tool, see here

Install sage, at least version 10

sage --python -m pip install -r requirements.txt

sage --python -m gunicorn -w 4 flask_app:app also available as ./server.sh

See skolem.mpi-sws.org

The input format is common between the following two tools.

Line 1: OrderOfLRS space separated coefficients of the recurrence Line 2: OrderOfLRS space separated initial numbers

9 -10 522 -4745 4225 -6 -12 3066 -768 -15366

encodes

u_{n} =9u_{n-1} + -10u_{n-2} + 522u_{n-3} + -4745u_{n-4} + 4225u_{n-5} With initial values : [-6, -12, 3066, -768, -15366]

Solves Skolem for (nearly) all simple LRS

• Usage by file: sage skolemtool.py flags filename, for example sage skolemtool.py -L fibonacci.eg
• Usage by server, see above.

Currently hosted at skolem.mpi-sws.org via flask_app.py.