Thanks. But I'm getting strange results from the second solution to the quadratic. And I've tried two more examples with the same happening again. I'm just trying to make sense of all my paperwork; then I'll post what I've found.
I didn't have to solve any quadratics...
It's something like logic programming except more specialized. And it seems it's often mixed with another paradigm (functional, imperative,...). The two languages mentioned on W are Oz, which is functional, and Kaleidoscope, which is imperative.
Oz seems really interresting.