Whitehead's algorithm

Whitehead's algorithm is a mathematical algorithm in group theory for solving the automorphic equivalence problem in the finite rank free group Fn. The algorithm is based on a classic 1936 paper of J. H. C. Whitehead.[1] It is still unknown (except for the case n = 2) if Whitehead's algorithm has polynomial time complexity.

  1. ^ J. H. C. Whitehead, On equivalent sets of elements in a free group, Ann. of Math. (2) 37:4 (1936), 782–800. MR1503309