It’s not string-related, but an optimization of this task is given by the “method of four Russians.” Cache-aware algorithms that perform this task may use “tiled” layouts of size equal to the square root of the cache size. In 2024, Virginia Vassilevska Williams’s team developed an algorithm for (10[1])this task that marginally improved a bound previously established by her and Alman. The search targets of Deepmind’s AlphaTensor system are efficient algorithms for this task, which seek to improve upon a divide-and-conquer algorithm (10[1])for this task that creates seven subproblems instead of an expected eight and was developed by Strassen. This task is equivalent to composing two linear transformations. For 10 points, name this non-commutative (10[1])operation that determines grid entries by taking inner products of rows and columns. ■END■ (10[2])