$XT\mapsto \begin{cases}1 & \text{if $X\ge T$}\\ 0 & \text{otherwise}\end{cases}$ $F(X, \mathrm{Ty})$ $aY$ $F(X, \mathrm{Ty})F(Y, \mathrm{Tz})$ $aZ$ $\mathrm{time}\ge 10$ $1$ $\mathrm{time}\ge 15$ $0$ $\mathrm{time}\ge 3.5$ $0$ $\mathrm{time}\ge 3$ $1$