code: def _vjp_sylvester(argnums, ans, args, _):
      a, b, q = args
  
      def vjp(g):
          vjps = []
          q_vjp = solve_sylvester(anp.transpose(a), anp.transpose(b), g)
          if 0 in argnums:
              vjps.append(-anp.dot(q_vjp, anp.transpose(ans)))
          if 1 in argnums:
              vjps.append(-anp.dot(anp.transpose(ans), q_vjp))
          if 2 in argnums:
              vjps.append(q_vjp)
          return tuple(vjps)
  
      return vjp
  
file_path: autograd/autograd/scipy/linalg.py
imports: from __future__ import division
  from functools import partial
  import scipy.linalg
  import autograd.numpy
  from autograd.numpy.numpy_wrapper import wrap_namespace
  from autograd.extend import defvjp, defvjp_argnums, defjvp, defjvp_argnums
label_desc: Use image node_id 7 for calling a global function with example usage: _vjp_sylvester(argnums, ans, args, _) and returns: vjp, tuple