Logics in Computer Science - Essay Example

Logics in Computer Science Question Backward Chaining Method Final target is Peter X 2. Mary Y 3. Frank Z Where X, Y and Z are the variables for the medicine administered. Step 1: X, Y and Z should suppress pain and / or Diarrhoea. Aspirin / alcohol and lomotil need to be administered to all the three. Step 2: X cannot aggravate peptic ulcer. This rules out aspirin. Therefore, Peter is administered alcohol for pain and lomotil for Diarrhoea. Y cannot impair lever-function. This rules out lomotil. Therefore, Mary is administered either aspirin or alcohol. Z cannot aggravate eczema. None of the medicines under consideration do that. Therefore, Frank can be administered any of the two pain killers and lomotil. 1. recommended (Peter, alcohol+lomotil) 2. recommended(Mary, aspirin) – there is no solution for diarrhoea. 3. recommended (Frank, aspirin+lomotil) Depth-first search strategy For Peter, he complains of pain and expands down the tree to aspirin. Aspirin aggravates peptic ulcer, so that tree is not possible. The next option is alcohol for pain and that is possible. Second, he also complains of diarrhoea and does not have impaired liver function, so lomotil is administered. Recommended(peter, alcohol+lomotil). Similarly, for Mary: recommended(mary, aspirin) – no medicine for diarrhoea. For Frank: recommended(frank, aspirin+lomotil). Question 2: Logic program Civil(x) not barbarians(y), educated(not drunk); Europeans(x,y)civil(x)V barbarians(y); Barbarians(x) football_supporters(x) unless educated(not drunk); Question 3 Situational Calculus The initial situation owns(X,Obj) V marbles(Y,R)  S0 do(Sells(X, Obj, Y, P), S0)  location(owns(Y, Obj), marbles(X, Q)); where Q>=P and R>=P; Read More