I think the approach eventually petered-out or was incorporated entirely into other approaches. But I have on my bookshelf Principles And Practice of Constrain

I think the approach eventually petered-out or was incorporated entirely into other approaches. But I have on my bookshelf Principles And Practice of Constraint Programming, edited by Saraswat and Van Hentenryck (1995) and wikipedia has an entry for the approach [1]. So the paradigm was up-and-coming for a time. A lot of ideas can rise and fall over forty years. Broadly, it was more or less part of logic programming, which was part of the symbolic/GOFAI (good old fashioned AI) paradigm, which naturally has been waning for many years. [1] https://en.wikipedia.org/wiki/Constraint_programming https://en.wikipedia.org/wiki/Constraint_programming