Assume¶
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class
sympy.assumptions.assume.
AppliedPredicate
[source]¶ The class of expressions resulting from applying a Predicate.
Examples
>>> from sympy import Q, Symbol >>> x = Symbol('x') >>> Q.integer(x) Q.integer(x) >>> type(Q.integer(x)) <class 'sympy.assumptions.assume.AppliedPredicate'>
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arg
¶ Return the expression used by this assumption.
Examples
>>> from sympy import Q, Symbol >>> x = Symbol('x') >>> a = Q.integer(x + 1) >>> a.arg x + 1
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class
sympy.assumptions.assume.
AssumptionsContext
[source]¶ Set representing assumptions.
This is used to represent global assumptions, but you can also use this class to create your own local assumptions contexts. It is basically a thin wrapper to Python’s set, so see its documentation for advanced usage.
Examples
>>> from sympy import AppliedPredicate, Q >>> from sympy.assumptions.assume import global_assumptions >>> global_assumptions AssumptionsContext() >>> from sympy.abc import x >>> global_assumptions.add(Q.real(x)) >>> global_assumptions AssumptionsContext([Q.real(x)]) >>> global_assumptions.remove(Q.real(x)) >>> global_assumptions AssumptionsContext() >>> global_assumptions.clear()
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class
sympy.assumptions.assume.
Predicate
[source]¶ A predicate is a function that returns a boolean value.
Predicates merely wrap their argument and remain unevaluated:
>>> from sympy import Q, ask, Symbol, S >>> x = Symbol('x') >>> Q.prime(7) Q.prime(7)
To obtain the truth value of an expression containing predicates, use the function \(ask\):
>>> ask(Q.prime(7)) True
The tautological predicate \(Q.is_true\) can be used to wrap other objects:
>>> Q.is_true(x > 1) Q.is_true(x > 1) >>> Q.is_true(S(1) < x) Q.is_true(1 < x)
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sympy.assumptions.assume.
assuming
(*args, **kwds)[source]¶ Context manager for assumptions
Examples
>>> from sympy.assumptions import assuming, Q, ask >>> from sympy.abc import x, y
>>> print(ask(Q.integer(x + y))) None
>>> with assuming(Q.integer(x), Q.integer(y)): ... print(ask(Q.integer(x + y))) True