module Accumulator:
input nickel, dime, gum;
output credit:integer;
var lcredit:integer in
    lcredit := 0;
    loop
        var nickelAmount,dimeAmount,gumAmount:integer in
            present nickel then nickelAmount := 5   else nickelAmount := 0 end present;
            present dime   then dimeAmount   := 10  else dimeAmount   := 0 end present;
            present gum    then gumAmount    := -15 else gumAmount    := 0 end present;
            lcredit := lcredit + nickelAmount + dimeAmount + gumAmount;
        end var;
        emit credit(lcredit);
        pause;
    end loop
end var
end module