It is probable that Lily is a lion. It is probably the case that John grabbed the apple. Chances are slight that Julius is yellow. We believe that if 'John grabbed the apple and Lily is a lion' then Fred is in the cinema. There is little chance that if 'Lily is a lion and Julius is yellow' then Sandra took the football. It is highly unlikely that if 'John grabbed the apple and Julius is yellow' then Bill went to the office.
It is probably the case that 'Fred is in the cinema and Lily is a lion'.
It is probably not the case that 'Fred is in the cinema and Lily is a lion'.
It is probably the case that 'Fred is in the cinema and Lily is a lion'.

  and(A,B) :- A,B.
  or(A,B) :- A;B.
  nand(A,B) :- not(and(A,B)).
  nor(A,B) :- not(or(A,B)).
  xor(A,B) :- or(A,B), nand(A,B).

  %hop0
  0.7::factA.
  0.7::factB.
  0.1::factC.
  %hop1
  0.75::factX:-and(factB,factA).
  0.1::factY:-and(factA,factC).
  0.05::factZ:-and(factB,factC).

  %hop2
  conclusion:-and(factX,factA).

  query(conclusion).
  
'Fred is in the cinema and Lily is a lion'.