### error using minimize_constrained

When I use minimize_constrained(), I get the following error:

```
File "", line 1, in <module>
File "/tmp/tmp81ftcX/___code___.py", line 72, in <module>
minimize_constrained(T, [_sage_const_1 ], nil)
File "/sagenb/sage_install/sage-4.8-sage.math.washington.edu-x86_64-Linux/local/lib/python2.6/site-packages/sage/numerical/optimize.py", line 415, in minimize_constrained
return vector(RDF,min)
UnboundLocalError: local variable 'min' referenced before assignment
```

It comes from the following piece of code:

```
K = matrix(K) # matrix of size (3*N+1)*(3*N+1)
des = vector(des) # vector of size 3*N+1
u = vector([var("u%02d" % k) for k in [0..3*N]]) # size 3*N+1
def LHS(X):
Y = 0.5*K*X*X - vector(des)*X
return Y
nul = [0 for j in range(0,3*N+1)]
minimize_constrained(LHS(u), [u02 -1], nil)
```

I don't understand why I keep getting the error for above function call (I know about global/local variables in python function calls, but definition of vector "u" makes it's elements global variables.)