context: It is improbable that Mary went to the office. It is unlikely that Bernhard is a rhino. It is certain that John took the football. It is probably the case that if 'Bernhard is a rhino and Mary went to the office' then Jessica is a cat. It is highly unlikely that if 'Mary went to the office and Bernhard is a rhino' then Julius is a swan. There is a very good chance that if 'Bernhard is a rhino and John took the football' then Brian is green.
hypothesis: It is unlikely that either 'Brian is green' or 'Jessica is a cat' but not both.
valid_hypothesis: It is unlikely that either 'Brian is green' or 'Jessica is a cat' but not both.
invalid_hypothesis: It is almost certain that either 'Brian is green' or 'Jessica is a cat' but not both.
problog: 
    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
    0.1::factA.
    0.2::factB.
    1.0::factC.
    %hop1
    0.7::factX:-and(factB,factA).
    0.05::factY:-and(factA,factB).
    0.8::factZ:-and(factB,factC).
  
    %hop2
    conclusion:-xor(factZ,factX).
  
    query(conclusion).
    
hypothesis_assertion: Either 'Brian is green' or 'Jessica is a cat' but not both.