A composite coincidence degree with applications to boundary value problems of neutral equations

L. H. Erbe, W. Krawcewicz, J. H. Wu
1993 Transactions of the American Mathematical Society  
We present a topological degree theory for the nonlinear problem L(I -B)(x) = G(x) with applications to a class of boundary value problems of neutral equations, where L is an unbounded Fredholm operator of index zero, B is condensing and G is L-compact.
doi:10.1090/s0002-9947-1993-1169080-3 fatcat:biy3kdo5zzb5jegam26qcffn4e