We doubt that Jason is tired. There is little chance that John took the apple. We doubt that Lily is green. It is probably the case that if 'John took the apple and Lily is green' then Mary went to the bedroom. We believe that if either 'Jason is tired' or 'John took the apple' but not both then Sandra left the football. Chances are about even that if 'Lily is green' or 'Jason is tired' or both then Greg is yellow.
It is probably not the case that either 'Lily is green' or 'Jason is tired' but not both.
It is probably not the case that either 'Lily is green' or 'Jason is tired' but not both.
There is a very good chance that either 'Lily is green' or 'Jason is tired' but not 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
  0.2::factA.
  0.1::factB.
  0.2::factC.
  %hop1
  0.7::factX:-and(factB,factC).
  0.75::factY:-xor(factA,factB).
  0.5::factZ:-or(factC,factA).

  %hop2
  conclusion:-xor(factC,factA).

  query(conclusion).
  
Either 'Lily is green' or 'Jason is tired' but not both.