Constant term
= Constant term
{title2=$\operatorname{CT}$}
The constant term of a <Laurent polynomial> is the coefficient of the <monomial> with exponent zero in every variable. Taking the constant term in just one variable leaves a <Laurent polynomial> in the other variables; successive extractions recover the full constant term. This operation is linear, but need not preserve products. The <Dyson constant-term identity> is a multivariate example of <coefficient extraction>.