| R0(H0, H1), R1(H2, H3), H0 ⊥ H2, H1 ⊥ H3 ⊦ (R0 * R1)(H0 ∪ H2, H1 ∪ H3) |
⊦ (R0 * R1)(H0, H1) ↔ (∃ H2, H3, H4, H5. H2 ⊥ H3 ∧ H4 ⊥ H5 ∧ H2 ∪ H3 = H0 ∧ H4 ∪ H5 = H1 ∧ R0(H2, H4) ∧ R1(H3, H5))
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (H1 ∪ H3, H0 ∪ H2, R1, R0)]]