Matrices as Tensor Network Diagrams
How would one write a cross-product with that?Using two vectors and the epsilon tensor (Levi-Chivita-symbol), I guess?Edit: So like this: two circles with one connection each as input, i.e. vectors (a and b), and a tensor with three connections, leaving one, meaning the result will be a vector again.  a  o
      \
       o -    (-o c)
      /
  b  o

Multiplying with another vector c gives the parallelepipedial product (a x b) c, a scalar (also = det(a,b,c)).Cool :)