Schemes:
    snap(s,n,a,p)
    NameHasID(n,s)

Facts:
    snap('12345','Snoopy','12 Apple','555-1234').
    snap('67890','Van Pelt','34 Pear','555-5678').

Rules:
    NameHasID(N,S):-snap(S,N,A,P).

Queries:
    snap('67890','Van Pelt','34 Pear','555-5678')?
    snap(S,N,A,P)?
    NameHasID('Snoopy',Id)?
    NameHasID(Name,'67890')?