6.0 macs:Mac OS X10.4.1 SntP 20 @x (/y (x = y) $ x = d) ; Do you see what this is trying to say about the ; world? (Notice the names.) You can't express ; that in the blocks language. Negate the whole ; sentence. @x @y ((Cube(x) & Cube(y)) $ /z Between(z, x, y)) ; Now this sentence tries to make a reasonable ; claim. Why is it false? Play the game and see. ; Then fix it so it says what was intended. @x (Between(x, d, c) $ x = b) @x (/y Between(x, y, c) $ x = b) @x (/y Between(x, y, c) $ ~Large(x)) @x (/y /z Between(x, y, z) $ ~Large(x)) @x (/y /z Between(x, y, z) $ Tet(x)) @x (~/y LeftOf(y, x) $ x = a) @x ((~/y LeftOf(y, x) & ~/y FrontOf(y, x)) $ x = a) @x (/y /z (Between(x, y, z) & Tet(y) & Tet(z)) $ x = e) @x (/y /z (Between(x, y, z) & Cube(y) & Cube(z)) $ x = b) @y (/x /z (Between(x, y, z) & x = b) $ (y = a | y = c)) @x @y ((Tet(x) & Small(x) & Tet(y) & Small(y)) $ x = y) ; Do you see what this says? @x @y ((Dodec(x) & Small(x) & Dodec(y) & Small(y)) $ x = y) ; If you understood the last one, you see why this is ; true as well. @x (Dodec(x) $ x = b) ; This may look like a dumb thing to say, but make ; sure you understand it. Why is it true? @x (Dodec(x) % x = b) ; And do you see why this is false? Under what ; circumstances would it be true? @x ((Tet(x) & Small(x)) % x = b) ; This time, we got it right. /y @x ((Tet(x) & Small(x)) % x = y) ; Compare this with the previous sentence. Do ; you understand what it says? Play the game ; a couple times, committed to both true and false. /y @x ((Cube(x) & Small(x)) % x = y) ; Play the game here, too. Do you see why you can't ; win when committed to true? ; In this slot, write a sentence that says there's ; exactly one large tetrahedron. Pattern it on ; sentence 18. s=294329;