A self-attention mechanism is configured to ensure that when processing a sequence, the output for any given position i is influenced only by inputs from positions j where j <= i. This prevents the model from 'seeing' future elements. The interaction between the query from position i and the key from position j results in a score. For a sequence of 4 elements (positions 0, 1, 2, 3), which of the following score matrices violates this principle? ('S' indicates a calculated score; '0' indicates a disallowed or masked interaction.)

Debugging an Autoregressive Model's Attention

In a self-attention mechanism designed to process information sequentially without looking ahead, a sequence of 8 elements (indexed 0 to 7) is being processed. The query vector for the element at position 5 will be compared against a total of ____ key vectors.