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POSolving Symbolic Boolean variables in Python
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copied!<p>I need to solve a set of symbolic Boolean expressions like:</p> <pre><code>>>> solve(x | y = False) (False, False) >>> solve(x & y = True) (True, True) >>> solve (x & y & z = True) (True, True, True) >>> solve(x ^ y = False) ((False, False), (True, True)) </code></pre> <p>Number of such variables is large (~200) so that Brute Force strategy is not possible. I searched the web and found that <a href="http://sympy.org/en/index.html" rel="nofollow">Sympy</a> and <a href="http://www.sagemath.org/index.html" rel="nofollow">Sage</a> have symbolic manipulation capabilities (particularly <a href="http://www.sagemath.org/doc/reference/logic/sage/logic/booleval.html" rel="nofollow">this</a> and <a href="http://www.sagemath.org/doc/reference/polynomial_rings/sage/rings/polynomial/pbori.html" rel="nofollow">this</a> may be useful). How can I do that?</p> <p>EDIT: I mainly tried to manipulate such things:</p> <pre><code>>>> from sympy import * >>> x=Symbol('x', bool=True) >>> y=Symbol('y', bool=True) >>> solve(x & y, x) </code></pre> <p>which results in <code>NotImplementedError</code>. Then I tried <code>solve(x * y, x)</code> which gave <code>[0]</code> (I don't know what does it mean), <code>solve(x * y = True, x)</code> resulted in a <code>SyntaxError</code>, <code>solve(x * y, True, x)</code> and <code>solve(x & y, True, x)</code> gave an <code>AttributeError</code>. I don't know what else to try!</p> <p>EDIT (2): I also found <a href="ftp://ftp.iitb.ac.in/packages/sagemath/doc/en/reference/sat/sat.pdf" rel="nofollow">this</a>, may be useful!</p>

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