Groucho Marx is surely funnier than Karl Marx¹, but is Plato also funnier than Karl Marx, and is Barbra Streisand funnier than Plato²?

Answer: Plato is funnier than Karl Marx, and Barbra Streisand is funnier than Plato.  (The answer is in black text on the black background. Highlight it to view.)

Citation: The Logic of Our Language: An Introduction to Symbolic Logic, 2014

¹ As of this post, there are only two Google results suggesting that Karl Marx is funnier than Groucho.  Alexander Baron notes, "Karl Marx is funnier than Groucho Marx in a sad kind of way."  And a certain Shovelhead says: "The EU: Where Karl Marx is funnier than Groucho."

² "Were space-time not linear and Plato could have Barbra Streisand speak next at that Athenian table (though of course he wouldn’t, as she’s a woman), he would undoubtedly have her sing 'People.'" —Richard Carpenter, "The Heart of the Matter"