 Moreover, developments in algebraic topology have often had wider implications, as for example in algebraic geometry and also in algebraic number theory.Such higher-dimensional (HHSvKT) theorems are about homotopy invariants of structured spaces, and especially those for filtered spaces or "n"-cubes of spaces.An example is the fact that the relative Hurewicz theorem is a consequence of HHSvKT, and this then suggested a triadic Hurewicz theorem.