ValueError: no symbols were given

[Neal Becker]

from sympy import *
fs, Rs, alpha = symbols ('fs', 'Rs', 'alpha')
fs1 = solve (Eq (fs - 2*Rs, fs/2 - Rs/2*(1+alpha)), fs)[0]
fs1_rs = simplify(fs1/Rs) # max sample/symbol with no filter

f1 = Rs/(2*fs)*(1+alpha) # passband edge of lp0
lp0_f0 = simplify(f1.subs (fs, fs1))
lp0_f1 = simplify(Rs/(fs).subs (fs, fs1)) # stopband edge of lp0

fs2 = solve (Eq (fs - 2*Rs, (1-lp0_f1)*fs - Rs/2*(1+alpha)))

gives this error on the last line:
---> 10 fs2 = solve (Eq (fs - 2*Rs, (1-lp0_f1)*fs - Rs/2*(1+alpha)))

/usr/lib/python2.6/site-packages/sympy-0.6.5-
py2.6.egg/sympy/solvers/solvers.pyc in solve(f, *symbols, **flags)
141 """
142 if not symbols:
--> 143 raise ValueError('no symbols were given')
144
145 if len(symbols) == 1:

ValueError: no symbols were given

[Neal Becker]

Sorry, my stupid error, please ignore