17/1 ⎇}<⎇[@]␈316417≤closure≥{ 18/1 ⎇}<⎇[@]␈316418≤open function≥{ 105/1 ⎇}<⎇[@]␈316420≤fixed-point operator≥{ 244/1 ⎇}<⎇[@]␈316423≤mutual recursion≥{ 285/1 ⎇}<⎇[@]␈316425≤special form≥{