| (a0[r => o] * R)[rs, f, g] ⊦ (a1[r => o] * R)[rs, f, g(r; a1)] ∧ g(r) = a0 |
⊦ (R0 * R1)[rs, f, g] ↔ (∃ rs0, rs1. rs0 ∪ rs1 = rs ∧ rs0 ∩ rs1 = ∅ ∧ R0[rs0, f, g] ∧ R1[rs1, f, g])
∃ rs0, rs1. rs0 ∪ rs1 = rs ∧ rs0 ∩ rs1 = ∅ ∧ a0[r => o][rs0, f, g] ∧ R[rs1, f, g] ⊦ (a1[r => o] * R)[rs, f, g(r; a1)] ∧ g(r) = a0
Used terms: g, f, rs, R, a0[r => o]