switching to high quality piper tts and added label translations

2026-01-29 23:48:19 +01:00
commit d80c619df9
3934 changed files with 1451600 additions and 0 deletions
@@ -0,0 +1,212 @@
+"""
+General binary relations.
+"""
+from typing import Optional
+
+from sympy.core.singleton import S
+from sympy.assumptions import AppliedPredicate, ask, Predicate, Q  # type: ignore
+from sympy.core.kind import BooleanKind
+from sympy.core.relational import Eq, Ne, Gt, Lt, Ge, Le
+from sympy.logic.boolalg import conjuncts, Not
+
+__all__ = ["BinaryRelation", "AppliedBinaryRelation"]
+
+
+class BinaryRelation(Predicate):
+    """
+    Base class for all binary relational predicates.
+
+    Explanation
+    ===========
+
+    Binary relation takes two arguments and returns ``AppliedBinaryRelation``
+    instance. To evaluate it to boolean value, use :obj:`~.ask()` or
+    :obj:`~.refine()` function.
+
+    You can add support for new types by registering the handler to dispatcher.
+    See :obj:`~.Predicate()` for more information about predicate dispatching.
+
+    Examples
+    ========
+
+    Applying and evaluating to boolean value:
+
+    >>> from sympy import Q, ask, sin, cos
+    >>> from sympy.abc import x
+    >>> Q.eq(sin(x)**2+cos(x)**2, 1)
+    Q.eq(sin(x)**2 + cos(x)**2, 1)
+    >>> ask(_)
+    True
+
+    You can define a new binary relation by subclassing and dispatching.
+    Here, we define a relation $R$ such that $x R y$ returns true if
+    $x = y + 1$.
+
+    >>> from sympy import ask, Number, Q
+    >>> from sympy.assumptions import BinaryRelation
+    >>> class MyRel(BinaryRelation):
+    ...     name = "R"
+    ...     is_reflexive = False
+    >>> Q.R = MyRel()
+    >>> @Q.R.register(Number, Number)
+    ... def _(n1, n2, assumptions):
+    ...     return ask(Q.zero(n1 - n2 - 1), assumptions)
+    >>> Q.R(2, 1)
+    Q.R(2, 1)
+
+    Now, we can use ``ask()`` to evaluate it to boolean value.
+
+    >>> ask(Q.R(2, 1))
+    True
+    >>> ask(Q.R(1, 2))
+    False
+
+    ``Q.R`` returns ``False`` with minimum cost if two arguments have same
+    structure because it is antireflexive relation [1] by
+    ``is_reflexive = False``.
+
+    >>> ask(Q.R(x, x))
+    False
+
+    References
+    ==========
+
+    .. [1] https://en.wikipedia.org/wiki/Reflexive_relation
+    """
+
+    is_reflexive: Optional[bool] = None
+    is_symmetric: Optional[bool] = None
+
+    def __call__(self, *args):
+        if not len(args) == 2:
+            raise ValueError("Binary relation takes two arguments, but got %s." % len(args))
+        return AppliedBinaryRelation(self, *args)
+
+    @property
+    def reversed(self):
+        if self.is_symmetric:
+            return self
+        return None
+
+    @property
+    def negated(self):
+        return None
+
+    def _compare_reflexive(self, lhs, rhs):
+        # quick exit for structurally same arguments
+        # do not check != here because it cannot catch the
+        # equivalent arguments with different structures.
+
+        # reflexivity does not hold to NaN
+        if lhs is S.NaN or rhs is S.NaN:
+            return None
+
+        reflexive = self.is_reflexive
+        if reflexive is None:
+            pass
+        elif reflexive and (lhs == rhs):
+            return True
+        elif not reflexive and (lhs == rhs):
+            return False
+        return None
+
+    def eval(self, args, assumptions=True):
+        # quick exit for structurally same arguments
+        ret = self._compare_reflexive(*args)
+        if ret is not None:
+            return ret
+
+        # don't perform simplify on args here. (done by AppliedBinaryRelation._eval_ask)
+        # evaluate by multipledispatch
+        lhs, rhs = args
+        ret = self.handler(lhs, rhs, assumptions=assumptions)
+        if ret is not None:
+            return ret
+
+        # check reversed order if the relation is reflexive
+        if self.is_reflexive:
+            types = (type(lhs), type(rhs))
+            if self.handler.dispatch(*types) is not self.handler.dispatch(*reversed(types)):
+                ret = self.handler(rhs, lhs, assumptions=assumptions)
+
+        return ret
+
+
+class AppliedBinaryRelation(AppliedPredicate):
+    """
+    The class of expressions resulting from applying ``BinaryRelation``
+    to the arguments.
+
+    """
+
+    @property
+    def lhs(self):
+        """The left-hand side of the relation."""
+        return self.arguments[0]
+
+    @property
+    def rhs(self):
+        """The right-hand side of the relation."""
+        return self.arguments[1]
+
+    @property
+    def reversed(self):
+        """
+        Try to return the relationship with sides reversed.
+        """
+        revfunc = self.function.reversed
+        if revfunc is None:
+            return self
+        return revfunc(self.rhs, self.lhs)
+
+    @property
+    def reversedsign(self):
+        """
+        Try to return the relationship with signs reversed.
+        """
+        revfunc = self.function.reversed
+        if revfunc is None:
+            return self
+        if not any(side.kind is BooleanKind for side in self.arguments):
+            return revfunc(-self.lhs, -self.rhs)
+        return self
+
+    @property
+    def negated(self):
+        neg_rel = self.function.negated
+        if neg_rel is None:
+            return Not(self, evaluate=False)
+        return neg_rel(*self.arguments)
+
+    def _eval_ask(self, assumptions):
+        conj_assumps = set()
+        binrelpreds = {Eq: Q.eq, Ne: Q.ne, Gt: Q.gt, Lt: Q.lt, Ge: Q.ge, Le: Q.le}
+        for a in conjuncts(assumptions):
+            if a.func in binrelpreds:
+                conj_assumps.add(binrelpreds[type(a)](*a.args))
+            else:
+                conj_assumps.add(a)
+
+        # After CNF in assumptions module is modified to take polyadic
+        # predicate, this will be removed
+        if any(rel in conj_assumps for rel in (self, self.reversed)):
+            return True
+        neg_rels = (self.negated, self.reversed.negated, Not(self, evaluate=False),
+            Not(self.reversed, evaluate=False))
+        if any(rel in conj_assumps for rel in neg_rels):
+            return False
+
+        # evaluation using multipledispatching
+        ret = self.function.eval(self.arguments, assumptions)
+        if ret is not None:
+            return ret
+
+        # simplify the args and try again
+        args = tuple(a.simplify() for a in self.arguments)
+        return self.function.eval(args, assumptions)
+
+    def __bool__(self):
+        ret = ask(self)
+        if ret is None:
+            raise TypeError("Cannot determine truth value of %s" % self)
+        return ret