Jim Blinn's Corner-uppers and downers. 2. (graphics)

The Feynman diagrams, which represent the product of tensors in diagram form as directed graphs, are described. In the diagrams, each tensor in the product is a node in the graph, each index is an arc, bound indices are arcs connecting the nodes, and free indices are dangling arcs. The epsilon-delta rule in diagram rotation is presented.<
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