Fig. 6From: Polynomial superlevel set representation of the multistationarity region of chemical reaction networksPSS representations of different degrees for the mulistationarity region of the LacI-TetR gene regulatory network using the information we got from the rectangular representation. The union of orange colored subrectangles is considered as the approximation of the multistationarity region obtained by the rectangular representation and chosen as the set K. The yellow colored area is the difference of \(U(p)-K\). a The rectangular representation of multistationarity region of the network with the system of equations given in (3) and some parameters being fixed by the values in (4). b–d PSS representations of the multistationarity region of degrees 2, 4 and 8 respectively obtained by the information of Fig. 6aBack to article page