y(peter) with 0.4.
y(mary) with 0.8.
h(X) <prod i(X) with 0.5.
h(peter) with 0.9.
h(mary) with 0.3.
e(peter) with 0.5.
e(mary) with 0.95.
i(X) <prod h(X) |prod e(X) with 1.
c(X) <prod i(X) &prod y(X) with 1.