as it is round (e.g. a human watching the horizon), and $r_1, r_2$ are experiences where the Earth is unlikely to be flat and likely to be round. We consider a population of 4 individuals with different knowledge-like functions $k_1, k_2, k_3$ and $k_4$ such as:

$$k_1(e) = \left\{ \begin{array}{ll}
        F & \mbox{if } e = f_1,\\
        0 & \mbox{otherwise},\\
    \end{array}
    \right.\quad k_2(e) = \left\{ \begin{array}{ll}
        F & \mbox{if } e = f_1 \text{ or } e = r_1,\\
        0 & \mbox{otherwise },\\
    \end{array}
    \right.$$

$$k_3(e) = \left\{ \begin{array}{ll}
        R & \mbox{if } e = f_1 \text{ or } e = r_1,\\
        0 & \mbox{otherwise},\\
    \end{array}
    \right.\quad k_4(e) = \left\{ \begin{array}{ll}
        F & \mbox{if } e = f_1, \\
        R & \mbox{if } e = r_1, \\
        0 & \mbox{otherwise.}\\
    \end{array}
    \right.$$

We now compute the credibility matrix, $$C = \begin{pmatrix}
1&1&1&1\\
\frac{1}{2}&0&1&1\\
\frac{1}{2}&0&1&\frac{1}{2}\\
\frac{1}{2}&0&1&1
\end{pmatrix}.$$

Let us normalize C such that its lines sum up to $1$, in order to easily read the influences on an individual $j$ in the row $i$: $$\title{C} = 
\begin{pmatrix}
\frac{1}{4}&\frac{1}{4}&\frac{1}{4}&\frac{1}{4}\\
\frac{1}{5}&0&\frac{2}{5}&\frac{2}{5}\\
\frac{1}{4}&0&\frac{1}{2}&\frac{1}{4}\\
\frac{1}{5}&0&\frac{2}{5}&\frac{2}{5}
\end{pmatrix}.$$

Individual \#1 has only experienced $f_1$, she judges the other individuals (and herself) regarding that sole experience. All individuals 