For a particular problem, I got some equations of the form $a = \min(1-b,0.9)$ $b = \max(\min(1-a,0.7)$, $\min(c, 0.8))$ $c = \max(\min(1-a,0.9)$, $\min(1-c, 0.9)) a,b,c \in [0,1]$ The system has a unique solution $a = 0.23333, b = 0.766666, c = 0.76666$.
Just wondering, how can I solve those equations in a general case.