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