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rodic(alfons,vera).
rodic(ema,vera).
rodic(alfons,emil).
rodic(ema,emil).
rodic(jiri,ivana).
rodic(jitka,ivana).
rodic(emil,cyril).
rodic(ivana,cyril).
rodic(bohumil,lenka).
rodic(cyril,zuzana).
rodic(lenka,zuzana).
rodic(cyril,otakar).
rodic(lenka,otakar).

zena(ema).
zena(jitka).
zena(vera).
zena(ivana).
muz(alfons).
muz(jiri).
muz(emil).
muz(bohumil).
muz(cyril).
muz(otakar).

prarodic(Prarodic,Vnouce) :- rodic(Prarodic,Rodic), rodic(Rodic,Vnouce).
vnouce(Vnouce,Prarodic) :- prarodic(Prarodic,Vnouce).
pravnouce(Pravnouce,Praprarodic) :- vnouce(Pravnouce,Prarodic),
    rodic(Praprarodic,Pravnouce).
sourozenec(X,Y) :- rodic(Rodic,X), rodic(Rodic,Y), X \= Y.
bratr(Bratr,Y) :- sourozenec(Bratr,Y), muz(Bratr).
teta(Teta,Y) :- rodic(Rodic,Y), sourozenec(Teta,Rodic), zena(Teta).