Rule muuzynibdvosvluw

input(How much is a $coffee and a $tea)
  && fact(A $coffee costs $x euros)
  && fact(A $tea costs $y euros)
  && $z = eval(formatDouble(parseDouble($x) + parseDouble($y), 2))
  => output($z Euros)

Loaded as

[id: muuzynibdvosvluw] input(How much is a $coffee and a $tea|How much is an $coffee and a $tea|How much is a $coffee and an $tea|How much is an $coffee and an $tea) && fact(a $coffee costs $x euros|an $coffee costs $x euros) && fact(a $tea costs $y euros|an $tea costs $y euros) && $z = eval(formatDouble(parseDouble($x) + parseDouble($y), 2)) => output($z Euros)