 The most famous of these is bounded truth-table reduction, but there are also bounded Turing, bounded weak truth-table and others.These first three are the most common ones and they are based on the number of queries.For example, a set "A" is bounded truth-table reducible to "B" if and only if the Turing machine "M" computing "A" relative to "B" computes a list of up to "n" numbers, queries "B" on these numbers and then terminates for all possible oracle answers; the value "n" is a constant independent of "x".