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MIT LICENSE

lstech_maple, Relaxed_newTech -- Copyright (c) 2019-2021, Shaowei Cai, Xindi Zhang.
Reference: Shaowei Cai, Xindi Zhang: Deep Cooperation of CDCL and Local Search for SAT.
Xindi Zhang, Shaowei Cai: Relaxed Backtracking with Rephasing.

MapleLCMDistChronoBT-DL, based on MapleLCMDistChronoBT -- Copyright (c) 2019, Stepan Kochemazov, Oleg Zaikin, Victor Kondratiev, Alexander Semenov: The solver was augmented with heuristic that moves duplicate learnt clauses into the core/tier2 tiers depending on a number of parameters.

MapleLCMDistChronoBT, based on Maple_LCM_Dist -- Copyright (c) 2018, Alexander Nadel, Vadim Ryvchin: "Chronological Backtracking" in SAT-2018, pp. 111-121.

Maple_LCM_Dist, Based on Maple_LCM -- Copyright (c) 2017, Fan Xiao, Chu-Min LI, Mao Luo: using a new branching heuristic called Distance at the beginning of search

Maple_LCM, Based on MapleCOMSPS_DRUP -- Copyright (c) 2017, Mao Luo, Chu-Min LI, Fan Xiao: implementing a learnt clause minimisation approach
Reference: M. Luo, C.-M. Li, F. Xiao, F. Manya, and Z. L. , “An effective learnt clause minimization approach for cdcl sat solvers,” in IJCAI-2017, 2017, pp. to–appear.

Chanseok Oh's MiniSat Patch Series -- Copyright (c) 2015, Chanseok Oh

MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
           Copyright (c) 2007-2010, Niklas Sorensson


Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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