\begin{definition}[Definition:Plastic Constant]
The '''plastic constant''' is the real root of the cubic:
:$x^3 - x - 1 = 0$
{{explain|There are $3$ roots of this equation -- needs to be established exactly which one we are talking about here.}}
Its value is approximately:
:$P = 1 \cdotp 32471 \, 795 \ldots$
{{OEIS|A060006}}
\end{definition}