1. 1> P = {adam,24,{july,29}}.
    2. {adam,24,{july,29}}
    3. 2> element(1,P).
    4. 3> element(3,P).
    5. {july,29}
    6. 4> P2 = setelement(2,P,25).
    7. 5> tuple_size(P).
    8. 3
    9. 6> tuple_size({}).