MONTY PYTHON AND THE (SEARCH FOR THE) HOLY GRAIL:
WITCHES BURN, AND WHAT ALSO BURNS?
WOOD?
YES, AND WOOD FLOATS, AND WHAT ELSE FLOATS?
A DUCK?
YES, AND BECAUSE A WITCH CAN BURN, AND WOOD BURNS, AND WOOD ALSO FLOATS, AND DUCKS FLOAT, THEN IF SHE IS A WITCH SHE WILL WEIGH AS MUCH AS A DUCK. FOCTS