Mastermind or Master Mind is a code-breaking game for two players. The modern game with pegs was invented in 1970 by Mordecai Meirowitz, an Israeli postmaster and telecommunications expert. It resembles an earlier pencil and paper game called Bulls and Cows that may date back a century or more.
pegs was invented in the early 20th century.
pegs was intended in the last 20th century, not the early. I think the system doesn't understand this concept of time.
( z1 invent :ARG1 ( z2 peg ) :time ( z3 early :op ( z4 date-entity :century 20 ) ) )