diff --git a/src/sage/rings/asymptotic/asymptotic_ring.py b/src/sage/rings/asymptotic/asymptotic_ring.py index c9cdbbdc7a3..d6c69f1e696 100644 --- a/src/sage/rings/asymptotic/asymptotic_ring.py +++ b/src/sage/rings/asymptotic/asymptotic_ring.py @@ -283,6 +283,33 @@ sage: (1 + 1/z + O(1/z^5))^(1 + 1/z) 1 + z^(-1) + z^(-2) + 1/2*z^(-3) + 1/3*z^(-4) + O(z^(-5)) +.. NOTE:: + + In the asymptotic ring + :: + + sage: M. = AsymptoticRing(growth_group='QQ^n * n^QQ', coefficient_ring=ZZ) + + the operation + :: + + sage: (1/2)^n + Traceback (most recent call last): + ... + ValueError: 1/2 is not in Exact Term Monoid QQ^n * n^QQ + with coefficients in Integer Ring. ... + + fails, since the rational `1/2` is not contained in `M`. You can use + :: + + sage: n.rpow(1/2) + (1/2)^n + + instead. Another way is to use a larger coefficent ring:: + + sage: M_QQ. = AsymptoticRing(growth_group='QQ^n * n^QQ', coefficient_ring=QQ) + sage: (1/2)^n + (1/2)^n Multivariate Arithmetic ^^^^^^^^^^^^^^^^^^^^^^^