For these questions the following functions have been defined.
\( la(x, y, z) = \min(x + y,\ y + z) \)
\( le(x, y, z) = \max(x - y,\ y - z) \)
\( ma(x, y, z) = \dfrac{1}{2}\big(le(x, y, z) + la(x, y, z)\big) \)
For \( x = 15,\ y = 10 \) and \( z = 9 \), find the value of \( le\big(x,\ \min(y,\ x - z),\ le(9,\ 8,\ ma(x, y, z))\big) \).