e/Claw-free permutation

Information
has gloss	eng: :f0(x) = f1(y) = z. A pair of permutations f0 and f1 are said to be claw-free if there is no efficient algorithm for computing a claw.
lexicalization	eng: claw-free permutation
instance of	(noun) act of changing the lineal order of objects in a group permutation