r ∈ H, r0 ∈ H ⊦ (r0 = r ⊃ H[r];H[r0]) = H[r0]
Used simplifier rules: in-write: ⊦ r ∈ H[r0, o] ↔ r ∈ H;%at-write: ⊦ H[r0, o][r] = (r = r0 ∧ r0 ∈ H ⊃ o;H[r]);