| ⊦ ri-inj(ri) → ( ri-inj(ri0) ↔ (∀ key0, key1. (key0 ∈ ri ∧ key1 ∈ ri ∧ ri[key0] = ri[key1] → key0 = key1) → key0 ∈ ri0 ∧ key1 ∈ ri0 ∧ ri0[key0] = ri0[key1] → key0 = key1)) |
ri-inj(ri) ⊦ ri-inj(ri0) ↔ (∀ key0, key1. (key0 ∈ ri ∧ key1 ∈ ri ∧ ri[key0] = ri[key1] → key0 = key1) → key0 ∈ ri0 ∧ key1 ∈ ri0 ∧ ri0[key0] = ri0[key1] → key0 = key1)