Among the significant physical results of combinatorial physics, we may mention the reinterpretation of renormalization as a Riemann–Hilbert problem, the fact that the Slavnov–Taylor identities of gauge theories generate a Hopf ideal, the quantization of fields and strings, and a completely algebraic description of the combinatorics of quantum field theory. An important example of applying combinatorics to physics is the enumeration of alternating sign matrix in the solution of ice-type models. The corresponding ice-type model is the six vertex model with domain wall boundary conditions.