Алгоритм для поиска формулы, которая соединяет входы и выходы

I seem to recall having learned a method for finding the formula that connects inputs and outputs from a table. For example:

a b c | r
1 1 0 | 0
0 1 1 | 1
1 1 1 | 1

where "r" is the result, and a, b and c are the inputs. The method involved equations with many unknowns and ended up with a formula that explained it all. (This is an example that is not that meaningful, since r = c, but you get the idea).

However, I can not remember the details, and not enough keywords to be able to find it on the web. The subject teaching this method also included a lot of boolean algebra.

I know this is a vague question, but what could this method for finding the formula from a table of values be?