3<p> a) PrimeMover(a) <br> <br>b) ∃x(PrimeMover(x)&∀y(PrimeMover(y)→y=x)) <br> <br>There is a Prime Mover, x, and for whatever y you choose, if y is a Prime Mover then y=x.<br><br>c) Now change the diagram. Click on the selection arrow, top left. Select the PrimeMover rectangle and move it slightly so as to move either a or b outside the rectangle. Have a look the Interpretation. Now run question (b) a second time i.e.<br><br> d) ∃x(PrimeMover(x)&∀y(PrimeMover(y)→y=x)) <br> <br>N.B. This shows the difference between "a" and "the".<br><br> e) ∃x∃y(PrimeMover(x)&PrimeMover(y)&~(x=y)&∀w(PrimeMover(w)→(w=x)∨(w=y))) <br> <br>Try Endorse-Denying this formula using the Interpretion you now have. Then press the button Reset Drawing and Try Endorse-Denying this formula a second time. </p>