  Epiphainein counts unreachable single-side pawn diagrams (in chess) where
pawns can move forward or diagonally-forward without limit whilst remaining on
the board. Epiphainein is a serial calculation and takes a few seconds to
calculate the number of unreachable diagrams on a regular 8 x 8 board. With a
decent machine it should take roughly 4 hours to calculate the same on a 10 x
10 board.
