context: It is highly likely that Sumit is hungry. It is highly likely that Yann is bored. Chances are about even that Lily is a lion. It is improbable that if 'Yann is bored and Sumit is hungry' then Mary left the apple. It is probably not the case that if either 'Lily is a lion' or 'Yann is bored' but not both then Sandra dropped the milk. It is highly unlikely that if 'Yann is bored and Lily is a lion' then Brian is a lion.
hypothesis: It is impossible that 'Sumit is hungry' or 'Yann is bored' or both.
valid_hypothesis: It is certain that 'Sumit is hungry' or 'Yann is bored' or both.
invalid_hypothesis: It is impossible that 'Sumit is hungry' or 'Yann is bored' or 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
    0.9::factA.
    0.9::factB.
    0.5::factC.
    %hop1
    0.1::factX:-and(factB,factA).
    0.25::factY:-xor(factC,factB).
    0.05::factZ:-and(factB,factC).
  
    %hop2
    conclusion:-or(factA,factB).
  
    query(conclusion).
    
hypothesis_assertion: 'Sumit is hungry' or 'Yann is bored' or both.