Correct checksol: add quick is_nonzero test

Fixes sympy/sympy#10391 checksol: use is_nonzero
diofant · Jan 15, 2016 · 1d56ea8 · 1d56ea8
1 parent 9a26aed
commit 1d56ea8
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diff --git a/sympy/solvers/solvers.py b/sympy/solvers/solvers.py
@@ -289,6 +289,8 @@ def checksol(f, symbol, sol=None, **flags):
             continue
         elif val.is_Rational:
             return val == 0
+        elif val.is_nonzero:
+            return False
         if numerical and not val.free_symbols:
             return bool(abs(val.n(18).n(12, chop=True)) < 1e-9)
         was = val

diff --git a/sympy/solvers/tests/test_solvers.py b/sympy/solvers/tests/test_solvers.py
@@ -1748,3 +1748,7 @@ def test_issue_8828():
 
     p, q, r = [{tuple(i.evalf(2) for i in j) for j in R} for R in [A, B, C]]
     assert p == q == r
+
+
+def test_issue_10391():
+    assert solve((2*x + 8)*exp(-6*x), x) == [-4]