a[rP(r)](mk(rs, f, g)) ⊦ (∃ r. rP(r)(mk(rs, f))) ∧ (r0 ∈ rs → g(r0) = a)
Used simplifier rules: ⊦ (_∃ rP)(H) ↔ (∃ r. rP(r)(H)); (s)