code: def cross1(c, a, b):
      c[0] = a[0] * b[2] - a[2] * b[1]
      c[1] = a[2] * b[0] - a[0] * b[2]
      c[2] = a[0] * b[1] - a[1] * b[0]
      return c
  
label_desc: Use image node_id 1 for calling a global function with example usage: cross1(c, a, b) and returns: c