∃x Fx, ¬ ∃x ∃y (¬ y = x ∧ (Fx ∧ Fy)) / ∃x (Fx ∧ ∀y (¬ y = x → ¬ Fy))
∃x Fx, ∃x Lx / ∃x (Fx ∧ Lx)
∃x (Fx ∧ Gx), ∃x (Gx ∧ Hx) / ∃x (Fx ∧ Hx)
∃x (Px ∧ Wax) / ∃x ((Px ∧ ¬ x = a) ∧ Wax)
∀x ∃y Rxy / ⊥