Kulikova, O.V.
(Algebra and Discrete Mathematics, 2003)
Let N₁ (respectively N₂) be a normal closure
of a set R₁ = {ui} (respectively R₂ = {vj}) of cyclically reduced
words of the free group F(A). In the paper we consider geometric
conditions on R₁ and R₂ for N₁ ∩ N₂ = [N₁, ...