Enginest focuses on data processing, artificial intelligence, operations research, logic programming and language analysis technologies. The fruit of such a technological combination is the NCL Natural Constraint Language.

The purpose of designing NCL is to offer users a Turing-complete description language in conventional mathematical logic, clean and easily accessible to beginners, for modeling and solving constraint satisfaction problems. NCL differs from other declarative languages: It models problems naturally in a simplified form of first-order logic with quantifiers, Boolean logic, numeric constraints, set operations and logical functions; it solves problems by mixed set programming over the mixed domain of real numbers, integers, Booleans, dates/times, references, and in particular sets. 

Distinguished with other commercial systems:

Mathematical parser: AI techniques support the recognition of natural mathematical expressions;

Mixed set programming: One of the world’s most sophisticated systems that integrates logical operations over the domains of real numbers, integers, Booleans, quantifiers, sets, logical functions, etc.

References

NCL's prototype was submitted in December 1997 to Third International Conference on Systems Science & Systems Engineering. The language was submitted in March 1998 to The Journal of Logic Programming (official journal of the Logic Programming Association).

Books: 

J. Zhou: The NCL Natural Constraint Language. Springer, ISBN 978-3-642-23844-4  (2012).

J. Zhou: The NCL Natural Constraint Language. Science Press Beijing(in Chinese), ISBN 978-7-03-024973-9 (2009).

Papers:

J. Zhou: Introduction to the constraint language NCL. Journal of Logic Programming. 45 (1-3): 71-103(2000).

J. Zhou: A unified framework for solving Boolean, integer & set constraints. Proc. of Third International Conference on Systems Science & Systems Engineering: 205-210 (1998).

J. Zhou: A Note on Mixed Set Programming. Proc. of The 7th International Symposium on Operations Research and Its Applications, 131-140 (2008).

J. Zhou: Routing By Mixed Set Programming. Proc. of The 8th International Symposium on Operations Research and Its Applications, 157-166 (2009).