<div id="comment:0"></div> The problem occured in context with #4618 (see comment 32) and is explained by the following code: ``` sage: L.<x> = LaurentSeriesRing(QQ) sage: q = x^2 + x^3 sage: q.add_bigoh(-1) Traceback (most recent call last): ... ValueError: prec (= -3) must be non-negative ``` CC: @tscrim Component: **algebra** Keywords: **Laurent series precision days100** Author: **Sebastian Oehms** Branch/Commit: **[`14878d5`](https://github.com/sagemath/sagetrac-mirror/commit/14878d5c2b583966e842214f0b0438921d21516b)** Reviewer: **Travis Scrimshaw** _Issue created by migration from https://trac.sagemath.org/ticket/28239_