Using SageMath 10.5, if I enter
R.<x,y>=PolynomialRing(QQ); f(x,y)=x+y; f in R
I would expect "f in R" to return either True or False. Instead it gives me a runtime error (message copied below). Is there a fix or workaround for this?
RuntimeError Traceback (most recent call last) <ipython-input-3-b05dc0c8ff91> in <module> ----> 1 f in R
/usr/lib/python3/dist-packages/sage/structure/parent.pyx in sage.structure.parent.Parent.__contains__ (build/cythonized/sage/structure/parent.c:10491)() 1162 try: 1163 x2 = self(x) -> 1164 EQ = (x2 == x) 1165 if EQ is True: 1166 return True
/usr/lib/python3/dist-packages/sage/structure/element.pyx in sage.structure.element.Element.__richcmp__ (build/cythonized/sage/structure/element.c:10491)() 1110 return (<element>self)._richcmp_(other, op) 1111 else: -> 1112 return coercion_model.richcmp(self, other, op) 1113 1114 cpdef _richcmp_(left, right, int op):
/usr/lib/python3/dist-packages/sage/structure/coerce.pyx in sage.structure.coerce.CoercionModel.richcmp (build/cythonized/sage/structure/coerce.c:20582)() 1971 # Coerce to a common parent 1972 try: -> 1973 x, y = self.canonical_coercion(x, y) 1974 except (TypeError, NotImplementedError): 1975 pass
/usr/lib/python3/dist-packages/sage/structure/coerce.pyx in sage.structure.coerce.CoercionModel.canonical_coercion (build/cythonized/sage/structure/coerce.c:12602)() 1330 if x_elt._parent is y_elt._parent: 1331 return x_elt,y_elt -> 1332 self._coercion_error(x, x_map, x_elt, y, y_map, y_elt) 1333 1334 cdef bint x_numeric = isinstance(x, (int, long, float, complex))
/usr/lib/python3/dist-packages/sage/structure/coerce.pyx in sage.structure.coerce.CoercionModel._coercion_error (build/cythonized/sage/structure/coerce.c:21337)() 2029 <class 'str'=""> 'g' 2030 """ -> 2031 raise RuntimeError("""There is a bug in the coercion code in Sage. 2032 Both x (=%r) and y (=%r) are supposed to have identical parents but they don't. 2033 In fact, x has parent '%s'
RuntimeError: There is a bug in the coercion code in Sage. Both x (=x + y) and y (=(x, y) |--> x + y) are supposed to have identical parents but they don't. In fact, x has parent 'Symbolic Ring' whereas y has parent 'Callable function ring with arguments (x, y)' Original elements x + y (parent Multivariate Polynomial Ring in x, y over Rational Field) and (x, y) |--> x + y (parent Callable function ring with arguments (x, y)) and maps <class 'sage.structure.coerce_maps.defaultconvertmap_unique'=""> (map internal to coercion system -- copy before use) Coercion map: From: Multivariate Polynomial Ring in x, y over Rational Field To: Callable function ring with arguments (x, y) <class 'nonetype'=""> None
