Concurrent Transaction Logic is an extension of  Sequential Transaction Logic that was developed by Anthony J. Bonner and Michael Kifer. It is a deductive database language that integrates queries, updates, and transaction composition in a simple logical framework.
The language supports all the properties of classical transaction, and also the properties found in many new transaction models, such as nested transactions, concurrency within individual transaction, cooperation between concurrent activities, a separation of atomicity and isolation, and fine-grained control over abort and rollback.

CTR Program

The CTR prototype is running on the XSB Prolog interpreter, currently the most efficient deductive database system. It is composed of the following 5 modules:

• main
• parser
• translator
• rollback
• interpreter
• optimizer 1
• optimizer 2

The prototype presented here is based on a simple, non-optimized interpreter for CTR. Source code, documentation and a description of this simple interpreter is available here.