From: Efficient path-based computations on pedigree graphs with compact encodings
1,
p 1 , p 2 , p 3 , q 1 , q 2
0.0,
p 2 , q 1
1,0.
p 3 , q 2
0.0,0.
p 2 , p 3 , q 1 , q 2