:-dynamic(case1/0).

case1 :- 
    retractall(pipe(_,_,_)),
    assert(pipe(a,10,1)),
    assert(pipe(b,5,1)),
    assert(pipe(c,20,2)).
	
:-dynamic(case2/0).
case2 :- 
    retractall(pipe(_,_,_)),
    assert(pipe(x,1000,10)).

:-dynamic(case3/0).
case3 :- 
    retractall(pipe(_,_,_)),
    assert(pipe(x,100,5)),
    assert(pipe(y,500,100)).
