| ⊦ (a[P] * a0[P0] * a1[P1] * R)[rs, f, g] ∧ a ≠ a0 ∧ a ≠ a1 ∧ a0 ≠ a1 → (a[P] * true)[rs, f, g] ∧ (a0[P0] * a1[P1] * true)[rs, f, g] |
(a[P] * a0[P0] * a1[P1] * R)[rs, f, g] ⊦ a = a1, a = a0, a0 = a1, (a[P] * true)[rs, f, g] ∧ (a0[P0] * a1[P1] * true)[rs, f, g]