title: Octave dsolve SymPy Error: Python exception: AttributeError: 'list' object has no attribute 'subs'
body: <p>(I tried posting this in <a href="https://scicomp.stackexchange.com/">Scientific Computing</a> but they said to post it here; sorry if this is again off-topic.)</p>
  
  <p>I'm using dsolve on Octave for the first time (Thanks so much for including this feature, BTW; this SimPy connection is just great), and it works fine with most of the ODEs and IVPs I've tried, but this one gives me an error:</p>
  
  <pre><code>&gt;&gt; pkg load symbolic
  &gt;&gt; syms x(t)
  &gt;&gt; ode1 = diff(x,t) == -t/x
  &gt;&gt; cond1 = x(0) == 5
  &gt;&gt; dsolve(ode1, cond1)
  error: Python exception: AttributeError: 'list' object has no attribute 'subs'
      occurred at line 15 of the Python code block error: called from
      python_cmd at line 176 column 5
      dsolve at line 200 column 10
  </code></pre>
  
  <p>Just solving the ODE worked fine; it only crashes with the IVP:</p>
  
  <pre><code>&gt;&gt; dsolve(ode1)
  ans =
  {
  (sym)
  
               _________
              ╱       2
    x(t) = -╲╱  C₁ - t
  
  (sym)
  
              _________
             ╱       2
    x(t) = ╲╱  C₁ - t
  </code></pre>
  
  <p>I tried other initial conditions, but got the same error:</p>
  
  <pre><code>&gt;&gt; cond2 = x(-3) == 0.1
  warning: Using rat() heuristics for double-precision input (is this what you wanted?)
  warning: called from
      sym at line 225 column 7
      binop_helper at line 60 column 5
      ineq_helper at line 35 column 5
      eq at line 91 column 5
  cond2 = (sym) x(-3) = 1/10
  &gt;&gt; dsolve(ode1, cond2)
  error: Python exception: AttributeError: 'list' object has no attribute 'subs'
      occurred at line 15 of the Python code block
  error: called from
      python_cmd at line 176 column 5
      dsolve at line 200 column 10
  </code></pre>
  
  <p>Can anyone help with this? I'd really like to use Octave to solve ODEs and IVPs explicitly</p>