I have long wanted to write a note on how factor graphs are great representations for both logic problems (satisfiability) and constraint satisfaction problems (sudoku puzzles etc.). Today I gave a guest lecture in Merrick Furst’s algorithms class -on this topic- so I thought this would be a great opportunity to pull some figures together and put it out there.

Hence, here is the link to a short Factor Graphs Primer in the domains of logic and CSPs. Note the CSP community prefers to call these “hyper-graphs”, just so you know...