$$\begin{aligned}
0 &= x_{\underline{\gamma}}(z)x_{\gamma}(z) - C \cdot x_{\underline{\delta}}(z)x_{\delta}(z)  \label{rell2} = \\ &= \sum_n \left( \sum_{p} (x_{\underline{\gamma}}(-n+p)x_{\gamma}(-p) - C \cdot x_{\underline{\delta}}(-n+p)x_{\delta}(-p) ) \right) z^{n-2} \notag. \end{aligned}$$

Therefore $$\begin{aligned}
& \label{rell3} \sum_p x_{\delta}(-n+p)x_{\gamma}(-p)=0 \qquad \textrm{and} \\ & \sum_{p} (x_{\underline{\gamma}}(-n+p)x_{\gamma}(-p) - C \cdot x_{\underline{\delta}}(-n+p)x_{\delta}(-p) ) =0\end{aligned}$$ for every $n$. The minimal monomials of this equalities, with regard to order introduced in Section \[order\], can now be expressed as the sum of other terms and so excluded from the spanning set. Such minimal monomials are called *the leading terms*.

For instance, relation gives us the following leading terms for $\delta \neq \underline{\gamma}$: $$\begin{aligned}
& x_{\delta}(-j)x_{\gamma}(-j)  \qquad \textrm{if $n$ is even and} \\
& x_{\delta}(-j-1)x_{\gamma}(-j)  \qquad \textrm{if $\delta \geq  \gamma$ and $n$ is odd}. \end{aligned}$$ This is clear when we remember that we first compare shapes and then colors of the monomials.

If the monomial $x(\pi)$ contains a leading term, this leading term can be replaced with an appropriate sum of greater monomials and so, using Proposition \[uredjaj\], it follows that $x(\pi)$ itself can be expressed as the sum of greater monomials. Therefore we conclude that monomials which contain the leading terms can be excluded from the spanning set. Monomials which don’t contain the leading 