On Syllogism.
The forms of categorical propositions already deduced are
| y = vx, | All Ys are Xs, |
| y = v(1 - x), | No Ys are Xs, |
vy = v'x, | Some Ys are Xs, |
vy = v'(1 - x), | Some Ys are not-Xs, |
whereof the two first give, by solution, 1 -
=
'(1 -
). All not-