We believe that Brian is a swan. It is highly likely that Jessica is a cat. It is likely that Mary went to the hallway. It is probably the case that if 'Mary went to the hallway' or 'Jessica is a cat' or both then Jeff moved to the garden. We doubt that if either 'Jessica is a cat' or 'Mary went to the hallway' but not both then Lily is yellow. It is certain that if 'Jessica is a cat' or 'Mary went to the hallway' or both then Emily is a sheep.
There is little chance that 'Mary went to the hallway' or 'Jessica is a cat' or both.
It is almost certain that 'Mary went to the hallway' or 'Jessica is a cat' or both.
There is little chance that 'Mary went to the hallway' or 'Jessica is a cat' or both.

  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
  0.75::factA.
  0.9::factB.
  0.7::factC.
  %hop1
  0.7::factX:-or(factC,factB).
  0.2::factY:-xor(factB,factC).
  1.0::factZ:-or(factB,factC).

  %hop2
  conclusion:-or(factC,factB).

  query(conclusion).
  
'Mary went to the hallway' or 'Jessica is a cat' or both.