| ri[key0] = ri[key], ri-inj(ri), key ∈ ri, key ∈ ks, key0 ∈ ri ⊦ #(ri[ks] ∩ range(ri \ ks)) = 0, # ks = 0, ks = ∅, key0 ∈ ks |
⊦ ri-inj(ri) ↔ (∀ key0, key1. key0 ∈ ri ∧ key1 ∈ ri ∧ ri[key0] = ri[key1] → key0 = key1)
ri[key0] = ri[key], key0 ∈ ri, key ∈ ks, key ∈ ri, ∀ key0, key1. key0 ∈ ri ∧ key1 ∈ ri ∧ ri[key0] = ri[key1] → key0 = key1 ⊦ # ks = 0, #(ri[ks] ∩ range(ri \ ks)) = 0, ks = ∅, key0 ∈ ks
Used terms: ri