containment

[Martin R]

In combinat/free_module.py, CombinatorialFreeModule, I find the doctest below.

Do we *really* want that 5/3 is not in CombinatorialFreeModule(QQ,["a", "b"])???

Martin

    def __contains__(self, x):

        """
        TESTS::

            sage: F = CombinatorialFreeModule(QQ,["a", "b"])
            sage: G = CombinatorialFreeModule(ZZ,["a", "b"])
            sage: F.monomial("a") in F
            True
            sage: G.monomial("a") in F
            False
            sage: "a" in F
            False
            sage: 5/3 in F
            False
        """

        return parent(x) == self  # is self?

[dmo...@deductivepress.ca]

Yes. Elements of F are linear combinations of the basis vectors a and b. Since 5/3 is not such a linear combination, it is certainly not in F.

[Martin R]

Oh dear, I should have taken a break. Thank you.